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Co-Director of Program on Science and Global Security, Princeton University
June 1, 2018
U.S.-Russia Nuclear Forces and Arms Control Agreements

Nuclear Weapons: Who Has What at a Glance

June 2023

Contact: Kelsey Davenport, Director for Nonproliferation Policy, (202) 463-8270 x102; Daryl G. Kimball, Executive Director, (202) 463-8270 x107.

At the dawn of the nuclear age, the United States hoped to maintain a monopoly on its new weapon, but the secrets and the technology for building the atomic bomb soon spread. The United States conducted its first nuclear test explosion in July 1945 and dropped two atomic bombs on the cities of Hiroshima and Nagasaki, Japan, in August 1945. Just four years later, the Soviet Union conducted its first nuclear test explosion. The United Kingdom (1952), France (1960), and China (1964) followed. Seeking to prevent the nuclear weapon ranks from expanding further, the United States and other like-minded countries negotiated the nuclear Nonproliferation Treaty (NPT) in 1968 and the Comprehensive Nuclear Test Ban Treaty (CTBT) in 1996.

India, Israel, and Pakistan never signed the NPT and possess nuclear arsenals. Iraq initiated a secret nuclear program under Saddam Hussein before the 1991 Persian Gulf War. North Korea announced its withdrawal from the NPT in January 2003 and has successfully tested advanced nuclear devices since that time. Iran and Libya have pursued secret nuclear activities in violation of the treaty’s terms, and Syria is suspected of having done the same. Still, nuclear nonproliferation successes outnumber failures, and dire decades-old forecasts that the world would soon be home to dozens of nuclear-armed states have not come to pass.

At the time the NPT was concluded, the nuclear stockpiles of both the United States and the Soviet Union/Russia numbered in the tens of thousands. Beginning in the 1970s, U.S. and Soviet/Russian leaders negotiated a series of bilateral arms control agreements and initiatives that limited, and later helped to reduce, the size of their nuclear arsenals. 

Today, the United States deploys 1,419 and Russia deploys 1,549 strategic warheads on several hundred bombers and missiles, and are modernizing their nuclear delivery systems. Warheads are counted using the provisions of the New START agreement, which was extended for 5 years in January 2021. Russia suspended its participation in the treaty on Feb. 21, 2023; in response, the United States instituted countermeasures limiting information sharing and inspections. However, both the U.S. and Russia have committed to the treaty’s central limits on strategic force deployments until 2026.

New START caps each country at 1,550 strategic deployed warheads and attributes one deployed warhead per deployed heavy bomber, no matter how many warheads each bomber carries. Warheads on deployed ICBMs and SLBMs are counted by the number of re-entry vehicles on the missile. Each re-entry vehicle can carry one warhead.


The United States, Russia, and China also possess smaller numbers of non-strategic (or tactical) nuclear warheads, which are shorter-range, lower-yield weapons that are not subject to any treaty limits.

China, India, and Pakistan are all pursuing new ballistic missiles, cruise missiles, and sea-based nuclear delivery systems. North Korea continues its nuclear pursuits in violation of its earlier denuclearization pledges.

The world's nuclear-armed states possess a combined total of about 12,512 nuclear warheads. 

Nuclear-Weapon States:

The nuclear-weapon states (NWS) are the five states—China, France, Russia, the United Kingdom, and the United States—officially recognized as possessing nuclear weapons by the NPT. The treaty recognizes these states’ nuclear arsenals, but under Article VI of the NPT, they are not supposed to build and maintain such weapons in perpetuity. In 2000, the NWS committed themselves to an “unequivocal undertaking…to accomplish the total elimination of their nuclear arsenals.” Because of the secretive nature with which most governments treat information about their nuclear arsenals, most of the figures below are best estimates of each nuclear-weapon state’s nuclear holdings, including both strategic warheads and shorter-range and lower-yield nuclear bombs, generally referred to as tactical nuclear weapons.


  • According to the September 2022 New START declaration, Russia deploys 1,549 strategic warheads on 540 strategic delivery systems (intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers). Due to Russia’s suspension of the New START Treaty in February 2022, it did not fulfill its treaty obligations to provide updated data. However, both Russia and the United States have committed to adhering by treaty limits until 2026. 
  • The U.S. intelligence community assesses that, as of December 2022, Russia also maintains an arsenal of 1000-2000 non-strategic nuclear warheads not limited by the New START Treaty. 
  • The Federation of American Scientists (FAS) estimates that Russia's military stockpile consists of approximately 4,489 nuclear warheads, with 1,400 additional retired warheads awaiting dismantlement, as of May 2023.

United States

  • According to the March 2023 New START declaration, the United States deploys 1,419 strategic nuclear warheads on 662 strategic delivery systems (intercontinental ballistic missiles, submarine-launched ballistic missiles, and heavy bombers).
  • The United States also has an estimated 100 B-61 nuclear gravity bombs that are forward-deployed at six NATO bases in five European countries: Aviano and Ghedi in Italy; Büchel in Germany; Incirlik in Turkey; Kleine Brogel in Belgium; and Volkel in the Netherlands. 
  • On October 5, 2021, the U.S. State Department issued a declassification announcement indicating that the total number of U.S. “active” and “inactive” warheads is 3,750 as of September 2020. The stockpile figures do not include retired warheads and those awaiting dismantlement. FAS estimates the current military stockpile stands at 3708 warheads, with 1,536 retired warheads awaiting dismantlement, for a total of 5,244 warheads as of early 2023.


  • Independent researchers estimate that China has approximately 410 nuclear warheads for delivery by land-based ballistic missiles, sea-based ballistic missiles, and bombers. Of that total, they estimate China has approximately 201 strategic launchers (intercontinental ballistic missiles and submarine-launched ballistic missiles.) Additional warheads are thought to be in production to eventually arm additional road-mobile and silo-based missiles and bombers.
  • Since the 1990s, China has continually modernized its nuclear forces, though the number and types of weapons fielded have expanded significantly in recent years. As of October 2023, the Defense Department assessed that China has a total of 500 nuclear weapons and, if it remains on its current trajectory, may have up to 1000 deliverable nuclear warheads by 2030.


  • France has a military stockpile of 290 operational warheads available for deployment on 98 strategic delivery systems, as of January 2022. This consists of 48 submarine-launched ballistic missiles, and 50 air-launched cruise missiles allocated for dual-capable land and carrier-based fighter aircraft. 
  • The French government has committed to a long-term modernization program for its nuclear forces but does not plan to increase the size of its nuclear stockpile. 

United Kingdom

  • As of January 2022, the United Kingdom has a military stockpile of 225 warheads, of which an estimated 120 are operationally available for deployment on 48 submarine-launched ballistic missiles, and 105 are in storage. 
  • The United Kingdom possesses a total of four Vanguard-class Trident nuclear-powered ballistic missile submarines, which together form its exclusively sea-based nuclear deterrent. 

Non-NPT Nuclear Weapons Possessors:

India, Pakistan, and Israel never joined the NPT and are known to possess nuclear weapons. India first tested a nuclear explosive device in 1974. That test spurred Pakistan to ramp up work on its secret nuclear weapons program. India and Pakistan both publicly demonstrated their nuclear weapon capabilities with a round of tit-for-tat nuclear tests in May 1998. Israel has not publicly conducted a nuclear test but is universally believed to possess nuclear arms. 

The following arsenal estimates are based on the amount of fissile material—highly enriched uranium and plutonium—that each of the states is estimated to have produced. Fissile material is the key element for making nuclear weapons. India and Israel are believed to use plutonium in their weapons, while Pakistan is thought to use highly enriched uranium.




  • Israel is estimated to have 90 nuclear warheads, with fissile material stockpiles of over 200.
  • Israel does not admit nor deny having nuclear weapons, and states that it will not be the first to introduce nuclear weapons in the Middle East. Nevertheless, Israel is universally believed to possess nuclear arms stored in a partially disassembled state, although it is unclear exactly how many.

States that Declared Their Withdrawal from the NPT:

North Korea joined the NPT as a non-nuclear weapon state but announced its withdrawal from the NPT in 2003 --a move that has not been legally recognized by the other NPT member states. North Korea has tested nuclear devices and nuclear-capable ballistic missiles. Uncertainty persists about how many nuclear devices North Korea has assembled.

North Korea

  • North Korea is estimated to have approximately 30 nuclear warheads and likely possesses additional fissile material that is not weaponized.
  • There is a high degree of uncertainty surrounding North Korea's fissile material stockpile and production. 
  • North Korea operates its 5-megawatt heavy-water graphite-moderated reactor to extract plutonium for its nuclear warheads and has done so on an intermittent basis since August 2013. North Korea has uranium enrichment technology and a known uranium enrichment facility at Yongbyon. It likely operates additional covert uranium enrichment facilities at other locations. 

States of Immediate Proliferation Concern:

Prior to the implementation of the Joint Comprehensive Plan of Action, Iran pursued a uranium enrichment program and other projects that provided it with the capability to produce weapons-grade fissile material and develop nuclear weapons, if it chose to do so. Since 2019, Iran has taken steps to breach limits put in place by the JCPOA and expanded its uranium enrichment program beyond its pre-JCPOA capacity. Tehran maintains that it does not intend to pursue nuclear weapons and that its actions are a response to the U.S. withdrawal from the nuclear deal and reimposition of sanctions. Iran continues to implement its comprehensive safeguards agreement with the IAEA, but suspended its additional protocol and certain JCPOA-specific measures in February 2021.


  • Iran has accumulated enough uranium enriched to 60 percent to build a nuclear weapon, but the warhead would be large, unwieldy, and inconsistent with the weapons-related work Iran did prior to 2003. Iran has not accumulated or enriched uranium to weapons-grade levels (90 percent). 
  • The International Atomic Energy Agency (IAEA), the institution charged with verifying that states are not illicitly building nuclear weapons, concluded in a 2015 report that Iran had an organized nucler weapons program prior to 2003, including activities related to uranium enrichment that should have been declared to the agency, and continued some weapons-relevant experiments through 2009. There was no evidence of weapons-related work after 2009, according to the IAEA.
  • On July 2015, Iran and the “P5+1” (China, France, Germany, Russia, the United Kingdom, and the United States) negotiated a long-term agreement to verify and significantly reduce Iran's capacity to produce material for nuclear weapons.
  • As part of this agreement, the IAEA and Iran concluded an investigation into Iran’s past nuclear weapons-related activities. The agency concluded that Iran had an organized program to pursue nuclear weapons prior to 2003. Some of these activities continued through 2009, but there were no indications of weaponization activities taking place after that date.
  • On May 8, 2018, President Trump announced that the United States would withdraw from the JCPOA. Iran began to violate the accord a year later. The United States and Iran have not yet reached an interim agreement to replace the JCPOA. Continued coverage of the JCPOA can be found in Arms Control Today and the P4+1 and Iran Nuclear Deal Alert

States That Had Nuclear Weapons or Nuclear Weapons Programs at One Time:

  • Belarus, Kazakhstan, and Ukraine inherited nuclear weapons following the Soviet Union’s 1991 collapse but returned them to Russia and joined the NPT as non-nuclear-weapon states.
  • The apartheid South African government secretly developed a small number of nuclear weapons. South Africa joined the NPT in 1991 and dismantled its entire nuclear weapons program prior to its transition to a multi-racial democracy in 1994. 
  • Iraq had an active nuclear weapons program prior to the 1991 Persian Gulf War but was forced to verifiably dismantle it under the supervision of UN inspectors. The United States invaded Iraq in 2003 under the Bush administration’s rationale of preventing Iraq from acquiring weapons of mass destruction. However, Iraq’s nuclear program had remained dormant since its dismantlement in the 1990s and the country did not have ready stockpiles of chemical or biological weapons.  
  • Libya voluntarily renounced its secret nuclear weapons efforts in December 2003.
  • Argentina, Brazil, South Korea, Sweden, Australia, and Taiwan also once pursued nuclear weapons programs.

Sources: Arms Control Association, Federation of American Scientists, International Panel on Fissile Materials, U.S. Department of Defense, U.S. Department of State, and Stockholm International Peace Research Institute.

Strategic Arms Control and Policy

Subject Resources:

The Intermediate-Range Nuclear Forces (INF) Treaty at a Glance

History of the INF Treaty between the United States and Russia and details on potential violations by Russia

Contact: Daryl Kimball, Executive Director, (202) 463-8270 x107

The 1987 Intermediate-Range Nuclear Forces (INF) Treaty required the United States and the Soviet Union to eliminate and permanently forswear all of their nuclear and conventional ground-launched ballistic and cruise missiles with ranges of 500 to 5,500 kilometers. The treaty marked the first time the superpowers had agreed to reduce their nuclear arsenals, eliminate an entire category of nuclear weapons, and employ extensive on-site inspections for verification. As a result of the INF Treaty, the United States and the Soviet Union destroyed a total of 2,692 short-, medium-, and intermediate-range missiles by the treaty's implementation deadline of June 1, 1991.

The United States first alleged in its July 2014 Compliance Report that Russia was in violation of its INF Treaty obligations “not to possess, produce, or flight-test” a ground-launched cruise missile having a range of 500 to 5,500 kilometers or “to possess or produce launchers of such missiles.” Subsequent State Department assessments in 2015, 2016, 2017, and 2018 repeated these allegations. In March 2017, a top U.S. official confirmed press reports that Russia had begun deploying the noncompliant missile. Russia has denied that it is in violation of the agreement and has accused the United States of being in noncompliance.

On Dec. 8, 2017, the Trump administration released an integrated strategy to counter alleged Russian violations of the treaty, including the commencement of research and development on a conventional, road-mobile, intermediate-range missile system. On Oct. 20, 2018, President Donald Trump announced his intention to “terminate” the INF Treaty, citing Russian noncompliance and concerns about China’s intermediate-range missile arsenal. On Dec. 4, 2018, Secretary of State Mike Pompeo announced that the United States found Russia in “material breach” of the treaty and would suspend its treaty obligations in 60 days if Russia did not return to compliance in that time. On Feb. 2, the Trump administration declared a suspension of U.S. obligations under the INF Treaty and formally announced its intention to withdraw from the treaty in six months. Shortly thereafter, Russian President Vladimir Putin also announced that Russia will be officially suspending its treaty obligations as well. 

On Aug. 2, 2019, the United States formally withdrew from the INF Treaty.

Early History

U.S. calls for the control of intermediate-range missiles emerged as a result of the Soviet Union's domestic deployment of SS-20 intermediate-range missiles in the mid-1970s. The SS-20 qualitatively improved Soviet nuclear forces in the European theater by providing a longer-range, multiple-warhead alternative to aging Soviet SS-4 and SS-5 single-warhead missiles. In 1979, NATO ministers responded to the new Soviet missile deployment with what became known as the "dual-track" strategy: a simultaneous push for arms control negotiations with the deployment of intermediate-range, nuclear-armed U.S. missiles (ground-launched cruise missiles and the Pershing II) in Europe to offset the SS-20. Negotiations, however, faltered repeatedly while U.S. missile deployments continued in the early 1980s. The INF Treaty prohibited all U.S. and Soviet missiles with ranges between 500 and 5,500 kilometers. The official figures above show missiles deployed November 1, 1987, shortly before the INF Treaty was signed. The treaty also required destruction of 430 U.S. missiles and 979 Soviet missiles which were in storage or otherwise not deployed. The treaty prevented the planned deployment of an additional 208 GLCMs in the Netherlands, Britain, Belgium, Germany, and Italy. The Pershing IAs, under joint U.S.-German control, were not formally covered by the INF Treaty but were also to be eliminated by U.S. and West German agreement.

INF Treaty negotiations began to show progress once Mikhail Gorbachev became the Soviet general-secretary in March 1985. In the fall of the same year, the Soviet Union put forward a plan to establish a balance between the number of SS-20 warheads and the growing number of allied intermediate-range missile warheads in Europe. The United States expressed interest in the Soviet proposal, and the scope of the negotiations expanded in 1986 to include all U.S. and Soviet intermediate-range missiles around the world. Using the momentum from these talks, President Ronald Reagan and Gorbachev began to move toward a comprehensive intermediate-range missile elimination agreement. Their efforts culminated in the signing of the INF Treaty on Dec. 8, 1987, and the treaty entered into force on June 1, 1988.

The intermediate-range missile ban originally applied only to U.S. and Soviet forces, but the treaty's membership expanded in 1991 to include the following successor states of the former Soviet Union: Belarus, Kazakhstan, and Ukraine, which had inspectable facilities on their territories at the time of the Soviet Union’s dissolution. Turkmenistan and Uzbekistan also possessed INF Treaty-range facilities (SS-23 operating bases) but forgo treaty meetings with the consent of the other states-parties.

Although active states-parties to the treaty total just five countries, several European countries have destroyed INF Treaty-range missiles since the end of the Cold War. Germany, Hungary, Poland, and the Czech Republic destroyed their intermediate-range missiles in the 1990s, and Slovakia dismantled all of its remaining intermediate-range missiles in October 2000 after extensive U.S. prodding. On May 31, 2002, the last possessor of intermediate-range missiles in Eastern Europe, Bulgaria, signed an agreement with the United States to destroy all of its INF Treaty-relevant missiles. Bulgaria completed the destruction five months later with U.S. funding.

States-parties' rights to conduct on-site inspections under the treaty ended on May 31, 2001, but the use of surveillance satellites for data collection continues. The INF Treaty established the Special Verification Commission (SVC) to act as an implementing body for the treaty, resolving questions of compliance and agreeing on measures to "improve [the treaty's] viability and effectiveness." Because the INF Treaty is of unlimited duration, states-parties could convene the SVC at any time.

Elimination Protocol

The INF Treaty's protocol on missile elimination named the specific types of ground-launched missiles to be destroyed and the acceptable means of doing so. Under the treaty, the United States committed to eliminate its Pershing II, Pershing IA, and Pershing IB ballistic missiles and BGM-109G cruise missiles. The Soviet Union had to destroy its SS-20, SS-4, SS-5, SS-12, and SS-23 ballistic missiles and SSC-X-4 cruise missiles. In addition, both parties were obliged to destroy all INF Treaty-related training missiles, rocket stages, launch canisters, and launchers. Most missiles were eliminated either by exploding them while they were unarmed and burning their stages or by cutting the missiles in half and severing their wings and tail sections.

Inspection and Verification Protocols

The INF Treaty's inspection protocol required states-parties to inspect and inventory each other's intermediate-range nuclear forces 30 to 90 days after the treaty's entry into force. Referred to as "baseline inspections," these exchanges laid the groundwork for future missile elimination by providing information on the size and location of U.S. and Soviet forces. Treaty provisions also allowed signatories to conduct up to 20 short-notice inspections per year at designated sites during the first three years of treaty implementation and to monitor specified missile-production facilities to guarantee that no new missiles were being produced.

The INF Treaty's verification protocol certified reductions through a combination of national technical means (i.e., satellite observation) and on-site inspections—a process by which each party could send observers to monitor the other's elimination efforts as they occurred. The protocol explicitly banned interference with photo-reconnaissance satellites, and states-parties were forbidden from concealing their missiles to impede verification activities. Both states-parties could carry out on-site inspections at each other's facilities in the United States and Soviet Union and at specified bases in Belgium, Italy, the Netherlands, the United Kingdom, West Germany, and Czechoslovakia.

The INF Treaty’s Slow Demise

Since the mid-2000s, Russia has raised the possibility of withdrawing from the INF Treaty. Moscow contends that the treaty unfairly prevents it from possessing weapons that its neighbors, such as China, are developing and fielding. Russia also has suggested that the proposed U.S. deployment of strategic anti-ballistic missile systems in Europe might trigger a Russian withdrawal from the accord, presumably so Moscow can deploy missiles targeting any future U.S. anti-missile sites. Still, the United States and Russia issued an Oct. 25, 2007, statement at the United Nations General Assembly reaffirming their “support” for the treaty and calling on all other states to join them in renouncing the missiles banned by the treaty.

Reports began to emerge in 2013 and 2014 that the United States had concerns about Russia's compliance with the INF Treaty. In July 2014, the U.S. State Department found Russia to be in violation of the agreement by producing and testing an illegal ground-launched cruise missile. Russia responded in August refuting the claim. Throughout 2015 and most of 2016, U.S. Defense and State Department officials had publicly expressed skepticism that the Russian cruise missiles at issue had been deployed. But an Oct. 19, 2016, report in The New York Times cited anonymous U.S. officials who were concerned that Russia was producing more missiles than needed solely for flight testing, which increased fears that Moscow was on the verge of deploying the missile. By Feb. 14, 2017, The New York Times cited U.S. officials declaring that Russia had deployed an operational unit of the treaty-noncompliant cruise missile now known as the SSC-8. On March 8, 2017, General Paul Selva, the vice chairman of the U.S. Joint Chiefs of Staff, confirmed press reports that Russia had deployed a ground-launched cruise missile that “violates the spirit and intent” of the INF Treaty.

The State Department’s 2018 annual assessment of Russian compliance with key arms control agreements alleged Russian noncompliance with the INF Treaty and listed details on the steps Washington has taken to resolve the dispute, including convening a session of the SVC and providing Moscow with further information on the violation.

The report says the missile in dispute is distinct from two other Russian missile systems, the R-500/SSC-7 Iskander GLCM and the RS-26 ballistic missile. The R-500 has a Russian-declared range below the 500-kilometer INF Treaty cutoff, and Russia identifies the RS-26 as an intercontinental ballistic missile treated in accordance with the New Strategic Arms Reduction Treaty (New START). The report also appears to suggest that the launcher for the allegedly noncompliant missile is different from the launcher for the Iskander. In late 2017, the United States for the first time revealed both the U.S. name for the missile of concern, the SSC-8, and the apparent Russian designation, the 9M729.

Russia denies that it breached the agreement and has raised its own concerns about Washington’s compliance. Moscow charges that the United States is placing a missile defense launch system in Europe that can also be used to fire cruise missiles, using targets for missile defense tests with similar characteristics to INF Treaty-prohibited intermediate-range missiles, and making armed drones that are equivalent to ground-launched cruise missiles.

Congress for the past several years has urged a more assertive military and economic response to Russia’s violation. The fiscal year 2018 National Defense Authorization Act (NDAA) authorized funds for the Defense Department to develop a conventional, road-mobile, ground-launched cruise missile that, if tested, would violate the treaty. The fiscal year 2019 NDAA also included provisions on the treaty. Section 1243 stated that no later than Jan. 15, 2019, the president would submit to Congress a determination on whether Russia is “in material breach” of its INF Treaty obligations and whether the “prohibitions set forth in Article VI of the INF Treaty remain binding on the United States.” Section 1244 expressed the sense of Congress that in light of Russia’s violation of the treaty, that the United States is “legally entitled to suspend the operation of the INF Treaty in whole or in part” as long as Russia is in material breach. For fiscal year 2020, the Defense Department requested nearly $100 million to develop three new missile systems that exceed the range limits of the treaty.

On Dec. 8, 2017 the Trump administration announced a strategy to respond to alleged Russian violations, which comprised of three elements: diplomacy, including through the Special Verification Commission, research and development on a new conventional ground-launched cruise missile, and punitive economic measures against companies believed to be involved in the development of the missile.

However, President Trump announced Oct. 20 that he would “terminate” the INF Treaty in response to the long-running dispute over Russian noncompliance with the agreement, as well as citing concerns about China’s unconstrained arsenal of INF Treaty-range missiles. Trump’s announcement seemed to take NATO allies by surprise, with many expressing concern about the president's plan. 

After repeatedly denying the existence of the 9M729 cruise missile, Russia has since acknowledged the missile but denies that the missile has been tested or is able to fly at an INF Treaty-range.

On Nov. 30, U.S. Director of National Intelligence Daniel Coats provided further details on the Russian treaty violation. Coats revealed that the United States believes Russia cheated by conducting legally allowable tests of the 9M729, such as testing the missile at over 500 km from a fixed launcher (allowed if the missile is to be deployed by air or sea), as well as testing the same missile from a mobile launcher at a range under 500 km. Coats noted that “by putting the two types of tests together,” Russia was able to develop an intermediate-range missile that could be launched from a “ground-mobile platform” in violation of the treaty.

On Dec. 4, Secretary of State Mike Pompeo announced that the United States found Russia in “material breach” of the treaty and would suspend its treaty obligations in 60 days if Russia did not return to compliance in that time. Though NATO allies in a Dec. 4 statement expressed for the first time the conclusion that Russia had violated the INF Treaty, the statement notably did not comment on Pompeo's ultimatum.

Russian President Vladimir Putin responded Dec. 5 by noting that Russia would respond “accordingly” to U.S. withdrawal from the treaty, and the chief of staff of the Russian military General Valery Gerasimov noted that U.S. missile sites on allied territory could become “targets of subsequent military exchanges." On Dec. 14, Reuters reported that Russian foreign ministry official Vladimir Yermakov was cited by RIA news agency as saying that Russia was ready to discuss mutual inspections with the United States in order to salvage the treaty. The United States and Russia met three more times after this, first in January in Geneva, on the sidelines of a P5 meeting in Beijing, and again in Geneva in July—all times to no new result.

On Feb. 2, President Trump and Secretary of State Pompeo announced that the United States suspended its obligations under the INF Treaty and will withdraw from the treaty in six months if Russia did not return to compliance. Shortly thereafter, Russian President Vladimir Putin also announced that Russia will be officially suspending its treaty obligations. 

Six months later, on Aug. 2, the United States formally withdrew from the INF Treaty. In a statement, Secretary Pompeo said, “With the full support of our NATO Allies, the United States has determined Russia to be in material breach of the treaty, and has subsequently suspended our obligations under the treaty.” He declared that “Russia is solely responsible for the treaty’s demise.” A day later, U.S. Secretary of Defense Mark Esper said that he was in favor of deploying conventional ground-launched, intermediate-range missiles in Asia “sooner rather than later.” 

Strategic Arms Control and Policy

Country Resources:

Subject Resources:

U.S.-Russian Nuclear Arms Control Agreements at a Glance

Contact: Daryl Kimball, executive director

Over the past five decades, U.S. and Soviet/Russian leaders have used a progression of bilateral agreements and other measures to limit and reduce their substantial nuclear warhead and strategic missile and bomber arsenals. The following is a brief summary.

Strategic Nuclear Arms Control Agreements


Begun in November 1969, the Strategic Arms Limitation Talks (SALT) produced two agreements by May 1972.

The Anti-Ballistic Missile (ABM) Treaty limited strategic missile defenses to 200 (later 100) interceptors each. In June 2002, the United States unilaterally withdrew from the ABM Treaty, feeling that it limited the country’s ability to defend itself against terrorist or “rogue-state” ballistic missile attacks.

Under the second negotiated deal, the Interim Agreement, both sides pledged not to construct new ICBM silos and not to increase the dimensions of existing ICBM silos “significantly,” as well as capped the number of SLBM launch tubes and SLBM-carrying submarines. The agreement ignored strategic bombers and did not address warhead numbers but succeeded in limiting the United States to 1,054 ICBM silos and the Soviet Union to 1,618 ICBM silos. The agreement also capped the number of SLBM launch tubes for each side and allowed for an increase in launchers if done alongside the dismantling or destruction of a corresponding number of older ICBM or SLBM launchers. The United States was limited to 710 SLBM launch tubes, from its base level of 656 SLBM launch tubes, and no more than 44 modern ballistic missile submarines. The Soviet Union was limited to 950 SLBM launch tubes, from its base level of 740 SLBM launch tubes, and no more than 62 modern ballistic missile submarines.


In November 1972, Washington and Moscow agreed to pursue a follow-on treaty to SALT I.

Signed in June 1979, SALT II would have limited U.S. and Soviet ICBM, SLBM, and strategic bomber-based nuclear forces to 2,250 delivery vehicles (defined as an ICBM silo, a SLBM launch tube, or a heavy bomber) and placed a variety of other restrictions on deployed strategic nuclear forces. The agreement would have required the Soviets to reduce their forces by roughly 270 delivery vehicles, but U.S. forces were below the limits and could actually have been increased.

U.S. President Jimmy Carter asked the Senate not to consider SALT II for its advice and consent after the Soviet Union invaded Afghanistan in December 1979, and the treaty was not taken up again. Both Washington and Moscow subsequently pledged to adhere to the agreement’s terms despite its failure to enter into force. However, U.S. President Ronald Reagan said on May 26, 1986 that future decisions on strategic nuclear forces would be based on the threat posed by Soviet forces and not on "a flawed SALT II Treaty.”


The Strategic Arms Reduction Treaty (START I), first proposed in the early 1980s by President Ronald Reagan and finally signed in July 1991, required the United States and the Soviet Union to reduce their deployed strategic arsenals to 1,600 delivery vehicles, carrying no more than 6,000 warheads as counted using the agreement’s rules.

The agreement required the destruction of excess delivery vehicles, which was verified using an intrusive verification regime that involved on-site inspections, the regular exchange of information (including telemetry), and the use of national technical means (i.e., satellites). The agreement’s entry into force was delayed for several years because of the collapse of the Soviet Union and the ensuing efforts to denuclearize Ukraine, Kazakhstan, and Belarus by returning their nuclear weapons to Russia and making them parties to the nuclear Nonproliferation Treaty (NPT) and START I agreements.

START I reductions were completed in December 2001, and the treaty expired on Dec. 5, 2009.


In June 1992, Presidents George H. W. Bush and Boris Yeltsin agreed to pursue a follow-on accord to START I.

START II, signed in January 1993, called for ultimately reducing deployed strategic arsenals to 3,000-3,500 warheads and banned the deployment of destabilizing multiple-warhead land-based missiles. START II would have counted warheads in roughly the same fashion as START I and, also like its predecessor, would have required the destruction of delivery vehicles but not warheads.

The agreement's original implementation deadline was January 2003, ten years after signature, but a 1997 protocol moved this deadline to December 2007 because of the extended delay in ratification. Both the Senate and the Duma approved START II, but the treaty did not take effect because the Senate did not ratify the 1997 protocol and several ABM Treaty amendments, whose passage the Duma established as a condition for START II’s entry into force. START II was effectively shelved as a result of the 2002 U.S. withdrawal from the ABM treaty.

START III Framework

In March 1997, Presidents Bill Clinton and Boris Yeltsin agreed to a framework for START III negotiations that included a reduction in deployed strategic warheads to 2,000-2,500.

Significantly, in addition to requiring the destruction of delivery vehicles, START III negotiations were to address “the destruction of strategic nuclear warheads” so as to promote the irreversibility of deep reductions. Negotiations were supposed to begin after START II entered into force, which never happened.

SORT (Moscow Treaty)

On May 24, 2002, Presidents George W. Bush and Vladimir Putin signed the Strategic Offensive Reductions Treaty (SORT or Moscow Treaty) under which the United States and Russia reduced their deployed strategic arsenals to 1,700-2,200 warheads each. The warhead limit took effect and expired on the same day, Dec. 31, 2012. As part of the agreement, the two countries also agreed to keep START I in force, which helped provide the monitoring and verification procedures left out of SORT.      

Although the two sides did not agree on specific counting rules, the Bush administration asserted that the United States would reduce only warheads deployed on strategic delivery vehicles in active service (i.e., “operationally deployed” warheads) and would not count warheads removed from service and placed in storage or warheads on delivery vehicles undergoing overhaul or repair. The agreement’s limits are similar to those envisioned for START III, but the treaty did not require the destruction of delivery vehicles, as START I and II did, or the destruction of warheads, as had been envisioned for START III.

The treaty was approved by the Senate and Duma and entered into force on June 1, 2003. SORT was replaced by New START on Feb. 5, 2011.


On April 8, 2010, the United States and Russia signed the New Strategic Arms Reduction Treaty (New START), a legally binding, verifiable agreement limiting each side to 1,550 strategic nuclear warheads deployed on 700 strategic delivery systems (ICBMs, SLBMs, and heavy bombers assigned to a nuclear mission) and limiting deployed and nondeployed launchers, including those in overhaul, to 800. The treaty does not limit non-deployed ICBMs and SLBMs.

The treaty-accountable warhead limit is 30 percent lower than the 2,200 upper limit of SORT, and the delivery vehicle limit is 50 percent lower than the 1,600 allowed in START I. The treaty has a verification regime that combines elements of START I with new elements tailored to New START. Measures under the treaty include on-site inspections and exhibitions, data exchanges and notifications related to strategic offensive arms and facilities covered by the treaty, and provisions to facilitate the use of national technical means for treaty monitoring. The treaty also provides for the continued exchange of telemetry (missile flight-test data on up to five tests per side, per year) and does not meaningfully limit missile defenses or long-range conventional strike capabilities.

The U.S. Senate approved New START on Dec. 22, 2010. The approval process of the Russian parliament (passage by both the State Duma and Federation Council) was completed Jan. 26, 2011. The treaty entered into force on Feb. 5, 2011, and both parties met the treaty’s central limits by the implementation deadline on Feb. 5, 2018. The United States and Russia agreed on Feb. 3, 2021, to extend New START by five years, as allowed by the treaty text, until Feb. 5, 2026.

Strategic Nuclear Arms Control Agreements

Strategic Nuclear Arms Control Agreements



Status Expired Never Entered Into Force Terminated Expired Never Entered Into Force Never Negotiated Replaced by New START In Force
Deployed Warhead Limit N/A N/A N/A 6,000 3,000-3,500 2,000-2,500 1,700-2,200 1,550
Deployed Delivery Vehicle Limit US: 1,764 ICBMs & SLBMs
USSR: 2,568
2,250 Prohibits ground-based missiles of 500-5,500 km range 1,600 N/A N/A N/A 700
Date Signed May 26, 1972 June 18, 1979 Dec. 8, 1987 July 31, 1991 Jan. 3, 1993 N/A May 24, 2002 April 8, 2010
Date Ratified, U.S. Aug. 3, 1972 N/A May 28, 1988 Oct. 1, 1992 Jan. 26, 1996 N/A March 6, 2003 Dec. 22, 2010
Ratification Vote, U.S. 88-2 N/A 93-6 93-6 87-4 N/A 95-0 71-26
Date Entered Into Force Oct. 3, 1972 N/A June 1, 1988 Dec. 5, 1994 N/A N/A June 1, 2003 Feb. 5, 2011
Implementation Deadline N/A N/A June 1, 1991 Dec. 5, 2001 N/A N/A N/A Feb. 5, 2018
Expiration Date Oct. 3, 1977 N/A Aug. 2, 2019 Dec. 5, 2009 N/A N/A Feb. 5, 2011 Feb. 5, 2026*

*Initially set to expire Feb. 5, 2021, New START was extended by five years until 2026 as allowed by the treaty text.

Non-strategic Nuclear Arms Control Measures

Intermediate-Range Nuclear Forces (INF) Treaty

Signed Dec. 8, 1987, the Intermediate-Range Nuclear Forces (INF) Treaty required the United States and the Soviet Union to verifiably eliminate all ground-launched ballistic and cruise missiles with ranges between 500 and 5,500 kilometers. Distinguished by its unprecedented, intrusive inspection regime, including on-site inspections, the INF Treaty laid the groundwork for verification of the subsequent START I. The INF Treaty entered into force June 1, 1988, and the two sides completed their reductions by June 1, 1991, destroying a total of 2,692 missiles. The agreement was multilateralized after the breakup of the Soviet Union, and active participants in the agreement came to include the United States, Russia, Belarus, Kazakhstan, and Ukraine. Turkmenistan and Uzbekistan were also parties to the agreement but did not participate in treaty meetings or on-site inspections with permission from the other states-parties. The ban on intermediate-range missiles was of unlimited duration.

Both the United States and Russia raised concerns about the other side’s compliance with the INF Treaty. The United States first publicly charged Russia in 2014 with developing and testing a ground-launched cruise missile—the 9M729 missile—with a range that exceeds the INF Treaty limits.

Russia denied that it breached the agreement and raised its own concerns about Washington’s compliance. Moscow charged that the United States placed a missile defense launch system in Europe that could also be used to fire interceptor and cruise missiles, using targets for missile defense tests with similar characteristics to INF Treaty-prohibited intermediate-range missiles, and was making armed drones that were equivalent to ground-launched cruise missiles.

On Oct. 20, 2018, President Donald Trump announced his intention to “terminate” the agreement citing Russian noncompliance and concerns about China’s missiles, and on Dec. 4, Secretary of State Mike Pompeo declared Russia in “material breach” of the treaty. The Trump administration provided official notice to the other treaty states-parties on Feb. 2, 2019, that it would both suspend its obligations to the treaty and withdraw from the agreement in six months—per the treaty's terms—and "terminate" the agreement unless Russia returned to compliance by eliminating its ground-launched 9M729 missiles.

On Aug. 2, 2019, the United States formally withdrew from the INF Treaty.

Presidential Nuclear Initiatives

On Sept. 27, 1991, President George H.W. Bush announced that the United States would remove almost all U.S. tactical (non-strategic) nuclear forces from deployment so that Russia could undertake similar actions, reducing the risk of nuclear proliferation as the Soviet Union dissolved. Specifically, Bush said the United States would eliminate all of its nuclear artillery shells and short-range ballistic missiles and remove all non-strategic nuclear warheads from surface ships, attack submarines, and land-based naval aircraft.

Soviet leader Mikhail Gorbachev reciprocated on Oct. 5, pledging to eliminate all nuclear artillery munitions, nuclear warheads for tactical missiles, and nuclear landmines. He also pledged to withdraw all Soviet tactical naval nuclear weapons from deployment.

Under these initiatives, the United States and Russia reduced their deployed non-strategic stockpiles by an estimated 5,000 and 13,000 warheads, respectively. However, significant questions remain about Russian implementation of its pledges, and there is considerable uncertainty about the current state of Russia’s tactical nuclear forces. The Defense Department estimates that Russia possesses roughly 1,900 non-strategic nuclear weapons and that the numbers are expanding. The United States maintains an estimated 200 non-strategic B61 gravity bombs.

Strategic Arms Control and Policy

Country Resources:

Russian Strategic Nuclear Forces Under New START

Contact: Shannon Bugossenior policy analyst[email protected]

On April 8, 2010, Russia and the United States signed the New Strategic Arms Reduction Treaty (New START). The treaty requires both sides to limit the number of deployed strategic nuclear warheads to no more than 1,550 and fielded delivery platforms to 700. The treaty also permits the United States and Russia to conduct 18 annual on-site inspections of facilities operated by the other country. Biannual data exchanges indicate the current state of their strategic forces.

As of March 1, 2022, Russia had 526 deployed strategic delivery systems, 1,474 deployed strategic nuclear warheads, and 761 deployed and non-deployed strategic launchers. Russia is in the process of both retiring many of its older strategic systems and replacing them with new systems.

For a factsheet on U.S. strategic nuclear forces under New START, click here.

Intercontinental Ballistic Missiles (ICBMs)

The following tables are based on public source data given that Russia does not release official statistics for specific New START accountable delivery systems. They are current as of early 2020 and sourced from russianforces.org.

Missile system

Number of systems

Warheads Total warheads


R-36M2 (SS-18)




Dombarovsky, Uzhur

Avangard/UR-100NUTTH (SS-19 Mod 4)





Topol (SS-25)




Barnaul, Vypolzovo

Topol-M silo (SS-27)





Topol-M mobile (SS-27)





RS-24 mobile




Teykovo, Yoshkar-Ola, Novosibirsk, Nizhniy Tagil, Irkutsk, Barnaul

RS-24 silo








up to 1181


Submarine-Launched Ballistic Missiles (SLBMs) and Submarines


As of early 2020, the Navy had 10 functional strategic submarines of three different types, of which 10 are functional and 1 is being overhauled. They are deployed with the Northern Fleet and the Pacific Fleet.

Bases of the Northern Fleet host five 667BDRM (Delta IV) submarines. One other Delta IV is undergoing overhaul. The Northern Fleet also hosts the lead submarine of the Project 955 class. The Pacific Fleet base hosts one 667BDR (Delta III) submarine and two Project 955 submarines.

Project 955 (also known as Borey or Yuri Dolgorukiy) is the newest class of submarines. Construction began in 1996, and the first joined the Northern Fleet in 2013, though subsequent submarines of this class have joined the Pacific Fleet in September 2015 and September 2016. As of January 2016, three Project 955 submarines have been accepted into service, with an additional four under construction.

When the missiles on Project 941 (Typhoon) class submarines reached the end of their service lives, these submarines were withdrawn from service. The one exception is the lead ship of the class, TK-208 Dmitry Donskoy, which was refitted for the new missile system, R-30 Bulava. This new system is designed for deployment on the Borey-class nuclear submarines. The Borey class submarines are expected to constitute the core of the Russian strategic submarine fleet, replacing the aging Project 941 and Project 667 boats. Russia is planning to build eight Borey and Borey-A class subs by 2020.

Submarine-Launched Ballistic Missiles

RIA News reported, in June 2012, that the Bulava sea-based ballistic missile had entered service. The Bulava (SS-NX-30) SLBM, developed by the Moscow Institute of Thermal Technology, carries up to 6 MIRV warheads and has a range of over 8,000 kilometers (5,000 miles). Borey class strategic submarines will carry up to 16 Bulava ballistic missiles, each with multiple warheads.

Strategic submarines

Number of submarines

Number of SLBMs and their type


Total warheads

Project  667BDR (Delta III)


16 R-29R (SS-N-18)



Project  667BDRM (Delta IV)


80 R-29RM (SS-N-23)



Project 941 (Typhoon)


- - -

- - - 

- - -

Project 955 (Borey)


48 R-30 Bulava







up to 656

[a] One submarine is undergoing overhaul and those missiles are not counted.
[b] One submarine of the Project 941 type has been refitted as a test bed for the Bulava missile system. It is not counted in the total number of operational submarines.

Strategic bombers

Russian Long-range Aviation Command consists of six divisions, two of which are the heavy-bomber divisions made up of Tu-160 and Tu-95MS aircraft. The Army has four divisions of Tu-22M3 (Backfire C) bombers.

As of early 2020, the Command is estimated to have 66 strategic bombers. The bombers can carry various modifications of the Kh-55 (AS-15) cruise missile and gravity bombs.


Number of bombers

Number of cruise missiles and their type

Total cruise missiles

Tu-95MS (Bear H)


Up to 16 Kh-55 (AS-15A)

No estimates available

Tu-160 (Blackjack)


12 Kh-55SM (AS-15B)

No estimates available





Strategic Arms Control and Policy

Country Resources:

U.S. Strategic Nuclear Forces Under New START

Contact: Shannon Bugossenior policy analyst[email protected]

    On April 8, 2010, Russia and the United States signed the New Strategic Arms Reduction Treaty (New START). The treaty requires the sides to limit the number of deployed strategic nuclear warheads to no more than 1,550 and fielded delivery platforms to 700. The treaty also permits the United States and Russia to conduct 18 annual on-site inspections of facilities operated by the other country. Biannual data exchanges indicate the current state of their strategic forces. For a factsheet on Russian nuclear forces, click here.

    Both the United States and Russia met these limits by the February 2018 deadline, and the limits will hold until February 2021.

    As of March 1, 2022, the United States has 686 deployed strategic delivery systems, 1,515 deployed strategic warheads, and 800 deployed and non-deployed strategic launchers.

    Under New START, the United States retains a deployed strategic force of up to 400 ICBMs, 60 nuclear-capable bombers, and 240 SLBMs.

    •  As of September 2020, the United States deploys 397 Minuteman III ICBMs, with 261 ICBMs in a non-deployed status, all of which have a single warhead. At any given time, an estimated 50 non-deployed silo launchers of ICBMs remain in a warm, operational status.

    •  Some bombers were converted to conventional-only missions (not accountable under New START), and 48 nuclear-capable bombers were deployed as of September 2020. Bombers are not on alert or loaded with weapons in peacetime, and New START counting rules allow each bomber to be counted as “one” deployed warhead, even though bombers can carry up to 16-20 nuclear weapons.

    •  The United States retains all 14 of its strategic nuclear submarines (SSBNs), although it reduced the number of SLBM launch tubes per SSBN from 24 to 20, for a total of 280 tubes across the entire fleet. Between two and four submarines are in dry dock at any given time. The United States deployed 230 submarine-launched ballistic missiles as of September 2020.

    In addition to the treaty limit of 700 deployed systems, the treaty allows for 800 deployed and non-deployed missile launchers, and bombers. As of September 2020, the United States retains 454 deployed and non-deployed ICBM launchers, 280 deployed and non-deployed SLBM launchers, and 66 deployed and non-deployed heavy bombers.

    The strategic forces that remain under the treaty are currently being upgraded or replaced. Over the 30 years, the administration plans to invest an estimated $1.7 trillion to modernize the nuclear weapons complex and nuclear delivery systems. For more on U.S. nuclear modernization, see U.S. Nuclear Modernization Programs.

    Under New START, both sides release aggregate data on their stockpiles every six months. 


    Table 1: Deployed U.S. Strategic Nuclear Forces Under New START 

    This table shows how the deployed U.S. strategic nuclear stockpile in 2017 and in 2018, when reductions under New START were completed.

    All figures are from official sources except for shaded warhead numbers, which are best estimates. New START counts each bomber as one warhead, even though bombers can carry many more.

      2017 2018

    Delivery Vehicles

    Est. Warheads

    Delivery Vehicles

    Est. Warheads


    Minuteman III

    (as of Sept. 1, 2017)



    (as of Feb. 2018)



    Trident II D5

    (as of Sept. 1, 2017)



    (as of Feb. 2018)


    Strategic Bombers


    (as of Sept. 1, 2017)



    (as of Feb. 2018)



    (as of Sept. 1, 2017)


    (as of Feb. 2018)

    Total Deployed

    (as of Sept. 1, 2017)

    (as of Sept. 1, 2017)


    (as of Sept. 2018)


    (as of Sept. 2018)

    Strategic Arms Control and Policy

    Country Resources:

    U.S. Nuclear Modernization Programs

    Contact: Shannon Bugossenior policy analyst, [email protected]


    Cost Overview

    The United States maintains an arsenal of about 1,700 strategic nuclear warheads deployed on intercontinental ballistic missiles (ICBMs) and submarine-launched ballistic missiles (SLBMs) and at strategic bomber bases. There are an additional estimated 100 non-strategic, or tactical, nuclear weapons at bomber bases in five European countries and about 2,000 nuclear warheads in storage.

    The Congressional Budget Office (CBO) estimated in May 2021 that the United States will spend a total of $634 billion over the next 10 years to sustain and modernize its nuclear arsenal, which is 28 percent higher than the previous 10-year projection released in 2019. This estimate in planned spending in fiscal years 2021–2030 is projected to consume 6.0–8.5 percent of projected total spending on national defense during those years. Over the next 30 years, the total sustainment and modernization costs of U.S. nuclear forces could reach $2 trillion.

    The CBO estimate captures spending on the triad of nuclear delivery systems and command and control systems at the Defense Department and on nuclear warheads and their supporting infrastructure at the Energy Department’s semi-autonomous National Nuclear Security Administration (NNSA). Nearly every element of the U.S. nuclear arsenal is slated to be upgraded over the next 20 years. Most of these efforts are in the early stages, and a few others have yet to begin.

    Other nuclear-armed states, notably Russia and China, are upgrading and may be posed to increase the size of their arsenals and have tested, produced, and deployed more brand new systems than the United States over the past decade. But the U.S. military has upgraded and refurbished nearly all of its existing strategic and tactical delivery systems and the warheads they carry to last well beyond their originally planned service life and is now in the early stages of replacing many of these aging systems with new systems. Though decades old, these modernized forces are more capable than the originals, and the new systems will include additional capability upgrades. The current and planned U.S. financial investment in nuclear forces is unrivaled by any other nuclear power.

    Gen. Paul Selva, then vice chairman of the Joint Chiefs of Staff, noted in testimony to the House Armed Services Committee in March 2017 that while Russia and China continue to modernize their nuclear forces, the United States maintains "a qualitative advantage."

    Former Vice Chairman of the Joint Chiefs of Staff, Gen. John Hyten, acknowledged in January 2019 that the United States still leads in most capabilities. However, he argued that the Defense Department must move quickly in order to keep up with “the speed” at which Russia and China are moving.

    The Trump administration, as outlined in its 2018 Nuclear Posture Review (NPR) released on Feb. 2, 2018, continued the modernization plan laid out by the Obama administration, as well as developed several new nuclear weapons capabilities that will add to the price tag for nuclear forces. This included the new low-yield nuclear warhead (the W76-2, which was deployed in 2019) for some submarine-launched ballistic missiles (SLBMs) and the longer-term development of a new nuclear submarine-launched cruise missile (SLCM).

    The Biden administration's first budget request proposed to continue every part of the unnecessary and unsustainable nuclear weapons spending plans it inherited from the Trump administration. This includes funding for development of the new nuclear SLCM, continued early development of a new high yield submarine launched ballistic missile warhead (the W93) and associated aeroshell, and sustainment of the B83-1 bomb.

    White House and Pentagon officials and defense budget watchers have expressed concern that the current triad modernization plans may not be executable in the absence of significant and sustained increases to overall military spending in the coming 15-20 years. This is in large part due to the fact that nuclear costs are scheduled to rise and overlap with a large "bow wave" in projected spending on conventional weapon system modernization programs, as well as rising personnel and readiness costs.

    Former head of U.S. Strategic Command Gen. Robert Kehler said in November 2017 that he is "skeptical that we are capable of remaining committed to a long-term project like this [nuclear modernization] without basically messing with it and screwing it up."

    The rising cost of the nuclear weapons mission is forcing hard choices for the Pentagon as to what other priorities must be cut back. In both the FY 2021 and FY 2022 budget requests, the Pentagon proposed cutting the Navy’s conventional shipbuilding account in order to pay for unplanned cost overruns for nuclear modernization.

    The NNSA warhead and infrastructure modernization effort in particular has experienced significant cost overruns and schedule delays. Spending on NNSA weapons activities grew by nearly 70 percent during the Trump administration.

    A 2018 U.S. Government Accountability Office (GAO) report issued in 2018 warned that the “NNSA’s plans to modernize its nuclear weapons do not align with its budget, raising affordability concerns.” And former agency administrator Frank Klotz said in a January 2018 interview given just two days after leaving office that the agency is “working pretty much at full capacity.”

    In March 2020, Allison Bawden from the GAO expressed to the House Armed Services Committee that the NNSA has “not addressed the projected bow wave of future funding needs and the mismatch between those needs and the potential funding available in the years in question.” As a result, Bawden said, “the NNSA raised questions about its ability to achieve its modernization program goals at cost and on schedule.”

    Nuclear Modernization Snapshot

    The overall nuclear modernization effort includes:

    • Modernized Strategic Delivery Systems: Existing U.S. nuclear delivery systems are undergoing continual modernization, including complete rebuilds of the Minuteman III ICBM and Trident II SLBM. The service lives of the Navy’s 14 Trident Ohio-class ballistic missile submarines are being extended. Additionally, a new submarine, the Columbia-class, which will replace the Ohio-class ballistic missile submarines, is undergoing development and is expected to cost $127 billion to acquire the 12-ship class, according to a March 2020 report by the Congressional Research Service. The B-2 strategic bomber, a relatively new system, is being upgraded, as is the B-52H bomber. The Air Force is also planning a new strategic bomber, the B-21 Raider, and a new nuclear-capable cruise missile, known as the Long-Range Standoff Weapon (LRSO) to replace the existing Air-Launched Cruise Missile (ALCM).
    • Refurbished Nuclear Warheads: The U.S. stockpile of nuclear warheads and bombs is continually refurbished through NNSA’s Life Extension Program (LEP). Existing warheads are certified annually to be safe and reliable. The NNSA is currently pursuing a controversial and expensive plan to refurbish or replace nearly every warhead type in the stockpile.
    • Modernized Production Complex: The nuclear weapons production complex is being modernized as well, with new facilities planned and funded. For example, the FY 2021 NNSA budget request includes $750 million for the Uranium Processing Facility (UPF) at Oak Ridge, Tennessee. The total construction cost for UPF is estimated at $6.5 – 7.5 billion, according to an independent study conducted by the Corps of Engineers, although some estimates put the price tag at $11 billion. NNSA has has pledged to complete construction by 2025 at a price tag of no more than $6.5 billion.
    • Command and Control Systems: The Defense Department maintains command, control, communications, and early-warning systems that allow operators to communicate with nuclear forces, issue commands that control their use, and detect or rule out incoming attacks. The 2018 NPR calls for placing greater attention and focus on sustaining and upgrading command and control capabilities. The CBO estimates that the Pentagon will need to spend $77 billion on these activities between FY 2019 and FY 2028 in order to implement the department’s plans.

    Nuclear Modernization Overview

    The following is a status update of existing programs to enhance the nuclear stockpile and modernize the delivery systems that make up each element of the U.S. nuclear triad.

    1. Intercontinental Ballistic Missiles (ICBMs)

    The United States Air Force currently deploys about 400 Minuteman III ICBMs (as of September 1, 2020) located across three wings: the 90th Missile Wing at F.E. Warren Air Force Base in Colorado, Nebraska, and Wyoming; the 341st Missile Wing at Malmstrom Air Force Base in Montana; and the 91st Missile Wing at Minot Air Force Base in North Dakota. U.S. nuclear-armed ICBMs are on high alert, meaning the missiles can be fired within minutes of a presidential decision to do so. Under New START, the United States maintains 50 extra missile silos in a "warm" reserve status.

    Today's Minuteman weapon system is the product of almost 40 years of continuous enhancement. The Pentagon has spent more than $7 billion over the past 15 years on life extension efforts to keep the ICBMs safe, secure, and reliable through 2030. This modernization program has resulted in an essentially "new" missile, expanded targeting options, and improved accuracy and survivability.

    Ground-Based Strategic Deterrent

    The Air Force is planning to replace the Minuteman III missile, its supporting launch control facilities, and command and control infrastructure with a program known as the Ground-Based Strategic Deterrent (GBSD) after 2030.

    The Air Force intends to purchase over 650 new missiles, 400 of which would be operationally deployed through the 2070s. The remaining missiles would be used for test flights and as spares. The service is seeking to make significant capability upgrades as part of the recapitalization program. The Pentagon in August 2016 set the estimated acquisition cost of the program at $85 billion and the total life-cycle cost at $238 billion (in then-year dollars). The $85 billion estimate is at the lower-end of an independent Pentagon cost-estimate that put the acquisition price tag as high as $150 billion. Bloomberg reported in October 2020 that the Pentagon has updated the estimated cost of the program to between $93.1 billion and $95.8 billion and the total life-cycle cost at $264 billion.

    The Air Force awarded contracts to both Boeing Company and Northrop Grumman to continue development and begin design of the new ICBM system in August 2017, but Boeing withdrew from the competition in July 2019. The Air Force awarded a $13.3 billion development contract to the Northrop in September 2020.

    Congress authorized $2.6 billion for the GBSD program for FY 2022.

    W78 and W87 Warheads

    The Air Force has also upgraded the Minuteman’s nuclear warheads by partially replacing older W78 warheads with newer and more powerful W87 warheads, formerly deployed on the now-retired MX Peacekeeper ICBMs. The W87 entered the U.S. stockpile in 1986, making it one of the newest warheads in the arsenal with the most modern safety and security features, including insensitive high explosive and a fire-resistant pit design, which can help to minimize the possibility of plutonium dispersal in the event of an accident. Under a 2004 LEP, the W87 warhead was refurbished to extend its service life past 2025.

    NNSA proposed a joint LEP to field a common, refurbished warhead to replace the W78 and W88 (see SLBMs, below). Congress approved NNSA's 2014 proposal to delay production of this warhead by five years from 2025 to 2030. However, the 2018 NPR proposed to accelerate the program by one year, and the NNSA begun work on a life extension program for the W78 warhead, calling it the W87-1 modification program in order to reflect the similar design to that warhead, in FY 2019 with a $53 million appropriation from Congress. In 2018, the NNSA dropped the proposal for a common warhead to focus solely on the W87-1 ICBM warhead.

    The W87-1 warhead is set to be fielded on the GBSD by 2030 and projected to cost $11-16 billion, not including the cost of producing new plutonium pits, which adds $14-28 billion.

    Congress authorized $691 million for this warhead modification program for FY 2022.

    2. Submarine-Launched Ballistic Missiles (SLBMs) and Submarines

    The Navy deploys, as of September 1, 2020, 230 Trident II D5 SLBMs. The Navy operates a total fleet of 14 Ohio-class ballistic missile submarines (SSBNs) based out of Bangor, Washington, (8 boats) and Kings Bay, Georgia (6 boats), though only 12 are considered operational at any given time. Four to five submarines are believed to be "on station" in the Atlantic and Pacific oceans ready to fire their missiles at targets at any given time.The Ohio-class submarines have a service life of 42 years — two 20-year cycles with a two-year mid-life nuclear refueling.

    The Ohio-class SSBNs were first deployed in 1981 and will reach the end of their services at a rate of approximately one boat per year between 2027 and 2040. The Navy plans to replace the Ohio-class starting in October 2030 with a new class of 12 ballistic missile submarines, now referred to as the Columbia-class. The Navy originally planned to begin using the replacement boats in 2029, but in 2012, the Pentagon announced a two-year delay to the replacement program. This pushed back completion of the first new submarine and its first deterrent patrol to 2031. The Navy has named the Columbia-class program its highest priority.

    The Navy purchased the first Columbia-class submarine in 2021 and plans to procure the second in 2024 and then one per year between 2026 and 2035. The first vessel is scheduled to become operational in 2031. As a result, the Navy will field 10 ballistic missile submarines between 2033 and 2042.

    Under New START, each Ohio-class submarine serves as a launch platform for up to 20 SLBMs loaded with up to eight warheads each, or 280 total SLBMs. The Columbia-class will carry up to 16 SLBMs, for a maximum of 192 deployed SLBMs when the fleet is fully converted to the new boats in 2042.

    In its FY 2021 budget request, the Navy stated that the procurement of the 12-ship Columbia-class will be $109.8 billion in then-year dollars. In 2017, however, the estimated the cost to develop and buy the submarines was $128 billion in then-year dollars, with the total life-cycle cost at $267 billion. A GAO report on the Columbia class program published in December 2017 warned that the program is not adequately funded to address program risks and that the acquisition cost is likely to exceed $128 billion. An April 2019 GAO report also concluded that the Navy’s estimate was “not reliable.”

    Congress authorized $5.1 billion for the program for FY 2022.

    Trident II D5 Submarine-Launched Ballistic Missiles

    First deployed in 1990, the force of Trident II D5 SLBMs has been successfully tested over 160 times since design completion in 1989 and is continuously evaluated. (By contrast, Russia's newest SLBM, the Bulava, has failed in roughly half its flight tests.) Each Trident ballistic missile can carry up to 8 warheads but normally carry an average of 3-4 warheads.

    First announced in 2002, the Trident II D5 life-extension program has been underway to modernize key components (notably the electronics), allow it to serve as the initial missile on the Columbia-class submarines, and extend the life of the missile until 2042. The first D5LE missiles were loaded onto the submarines in 2017.

    The Navy announced in 2019 that it would pursue a second life-extension program (D5LE2) for the missiles to ensure they can operate for another 60 years, through 2084.

    W76, W88, and W93 Warheads

    The D5 SLBMs are armed with approximately 1,511 W76-1, 25 W76-2, and 384 W88 warheads.

    The W76-1 warhead has an estimated yield of 90-100 kilotons and completed in 2019 a life-extension program to lengthen its service life for an additional 30 years. The new W76-2 warhead, first proposed in the 2018 NPR, has an estimated yield of 8 kilotons and was initially deployed at the end of 2019.

    The W88 warhead entered the stockpile in 1989. The first production unit of the W88 Alt 370 program—which replaces the arming, fuzing, and firing subsystem, refreshes the conventional high explosives within the weapon, and supports future life extension options—was initially scheduled for 2020, but did not occur until July 2021.

    The NNSA requested and received initial funding for a new W93 warhead (previously known as the “next Navy warhead”) in FY 2021, two years ahead of schedule. The Pentagon plans to have the new warhead eventually replace the W76 and W88 warheads on life-extended Trident II missiles. The Navy aims to also design a new reentry body, known as the MK7 aeroshell, to house the W93 when it is deployed on Trident II missiles.

    3. Strategic Bombers

    The United States Air Force operates a total fleet of 20 (of which 12 are deployed) B-2 Spirit bombers at Whiteman Air Force Base in Missouri, and 46 (of which 36 are deployed) nuclear-capable B-52H Stratofortress bombers at Minot Air Force Base, North Dakota, and Barksdale Air Force Base, Louisiana, that can all be equipped for nuclear missions as of September 1, 2020.

    B-52H Bomber

    First deployed in 1961, the B-52H fleet has an on-going modification program, beginning in 1989, to incorporate updates to the global positioning system, update the weapons capabilities to accommodate a full array of advanced weapons developed after the procurement of the B-52H, and modify the heavy stores adapter beams to allow the B-52H to carry up to 2,000 pound munitions and a total of 70,000 pounds of mixed ordnance armaments. The heavy bombers are currently receiving upgrades to their communications and electronics systems.

    The B-52H is no longer assigned to carry gravity bombs and instead can carry up to 20 air-launched cruise missiles. The Air Force operates a total of 87 B-52H bombers, with 46 being nuclear-capable and the rest conventional.

    The B-52H is expected to remain in service into the 2050s.

    B-2 Bomber

    The Air Force continually modernizes the B-2 fleet, which first became operational in 1997 and is expected to last through 2058.

    The B-2 bomber can carry up to 16 nuclear gravity bombs, both the B61 and B83, but not cruise missiles. The bomber can also carry conventional weapons.

    The Air Force announced in February 2018 that "once sufficient B-21 aircraft are operational, the B-1s and B-2s will be incrementally retired."

    B-21 Bomber

    The Air Force is planning to purchase at least 100 new, dual-capable long-range penetrating bombers that will begin to enter service in 2025 and replace the B-1 and B-2 bombers (and perhaps the B-52H in the future). The new bomber is known as the B-21 Raider. Much about this long-range bomber remains classified, including its speed, payload, stealthy characteristics, and production schedule. The Air Force awarded the contract to Northrop Grumman in October 2015 to begin developing the B-21 program.

    The Pentagon has estimated that the average procurement cost per aircraft to be around $550 million and the cost to develop, purchase, and operate 100 bombers over 30 years to be $203 billion (all in FY 2019 dollars). This latter cost includes $25.1 billion for development, $64 billion for production, and $114 billion for 30 years of sustainment and operation.

    The Air Force said in September 2021 that five B-21s were in production. Congress authorized $3 billion for the B-21 bomber program for FY 2022.

    Air-Launched Cruise Missile and Long-Range Standoff Cruise Missile

    The B-52H carries the AGM-86 air-launched cruise missile (ALCM), first deployed in 1982. Each ALCM carries a W80-1 warhead, first produced in 1982.

    As of 2021, the Air Force retains roughly 530 nuclear-capable ALCMs, of which roughly 200 are believed to be deployed at Minot Air Force Base in North Dakota.

    Some reports indicate that the reliability of the ALCM could be in jeopardy due to aging components which are becoming increasingly difficult to maintain.

    The Air Force is developing the long-range standoff cruise missile (LRSO) to replace the existing ALCM (AGM-86B) in 2030. The new missile will be compatible with the B-2 and B-52H bombers, as well as the planned B-21. The first missile is slated to be produced in 2026. The LRSO would carry the refurbished W80-4 warhead.

    The current Air Force procurement plan for the LRSO calls for about 1,000 new nuclear-capable missiles, roughly double the size of the existing fleet of ALCMs. According to the service, the planned purchase of 1,000 missiles includes far more missiles than it plans to arm and deploy with nuclear warheads.

    The Air Force announced in April 2020 that Raytheon would be the sole contractor for the development of the LRSO and awarded a $2 billion development contract to the company in July 2021.

    In 2016, the Pentagon projected the cost of the LRSO program to be about $11 billion (in then-year dollars). The department updated the cost assessment in 2021 to be between $14.2 billion and $16.2 billion (in then-year dollars). The 2021 projection did not include the cost of the W80-4 warhead, which is expected to cost an additional $11 billion.

    Congress authorized $609 million for the LRSO program for FY 2022 and $1.1 billion for the W80-4 LEP.

    B61 and B83 Warheads

    The B-2 carries the B61 and B83 strategic gravity bombs. The B61, first deployed in 1968, has several mods in the current stockpile: 3, 4, 7, and 11. The B61-3 and B61-4 are non-strategic weapons deployed in Europe for NATO aircraft as part of America’s extended nuclear commitment. The B61-7 and B61-11 are strategic weapons deployed on the B-2 bomber.

    The NNSA is conducting a life-extension program for the B61 to extend its life for an additional 20 years. The ongoing B61 LEP would combine mods 3, 4, and 7 into a single low-yield bomb, the B61-12, and ensure compatibility with the F-35 Joint Strike Fighter. The B61-12 began production in 2020 and completed the first production unit in November 2021. The LEP is expected to conclude in FY 2026.

    An assessment of the B61 LEP in 2016 put the direct cost of the program at $7.6 billion, an increase of $200 million over the NNSA’s estimate of $7.4 billion provided in its FY 2017 budget materials. The NNSA’s independent Office of Cost Estimating and Program Evaluation, however, told the GAO that its assessment of the program projects a total cost of approximately $10 billion and a two-year delay to the agency’s estimated March 2020 first production-unit date.

    The upgraded B61 will be equipped with a new tail-kit guidance assembly that will make the bomb more accurate and allow it to have a lower yield than some of the existing variants. The new tail kit is being developed by the Air Force and is estimated to cost $1.3 billion.

    The B83 was first produced in 1983, making it one of the newer weapons in the stockpile and the only remaining megaton-class weapon in the stockpile. The B83 has the most modern safety and security features, including insensitive high explosive and a fire-resistant pit.

    The Obama administration stated that the B83 would be retired once confidence in the B61-12 is projected to be achieved in the mid 2020s. However, the 2018 NPR reverses this decision and calls for retaining the B83 until a suitable replacement is found, and the Biden administration has not yet altered this plan. 


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    Hotline Agreements

    Contact: Daryl Kimball, Executive Director, (202) 463-8270 x107

    A hotline is a quick communication link between heads of states, which is designed to reduce the danger of an accident, miscalculation, or surprise attack, and especially an incident that might trigger a nuclear war.

    1963 U.S.-Soviet Memorandum of Understanding
    On June 20, 1963, the United States and the Soviet Union signed the "Memorandum of Understanding Between the United States of America and the Union of Soviet Socialist Republics Regarding the Establishment of a Direct Communications Link," also known as the hotline agreement. This agreement was designed to help speed up communications between the two governments and prevent the possibility of accidental nuclear war. It is no coincidence that the agreement came just a few months after the October 1962 Cuban missile crisis, when the United States and the Soviet Union came to the brink of nuclear conflict. The new agreement was designed to forestall such a crisis in the future.

    The hotline agreement held each government responsible for the arrangements for the communications link on their territories respectively. The hotline would comprise of two terminal points, Washington and Moscow, with both a full-time duplex wire telegraph circuit with teletype equipment routed between the two points via London, Copenhagen, Stockholm, and Helsinki and a full-time duplex radiotelegraph routed between them through Tangier. In case the wire circuit was interrupted, messages would be transmitted via radio circuit.

    American teleprinter machines were installed in the Kremlin to receive messages from Washington, which were in English; Soviet teleprinter machines were installed in the Pentagon to receive messages from Moscow, which were in Russian. Both nations also exchanged encoding devices in order to decipher the messages. The transmission of a message from one nation to another would take just a few minutes. The messages then were decoded and translated by the recipient country.

    It is a misleading belief that the hotline was a red telephone that sat in the Oval Office of the White House. The first generation of the hotline had no voice element and actually resided in the National Military Command Center in the Pentagon. The countries decided against the use of a telephone as the leaders would rely too much on rapid translation, while using telegraphs instead would allow time to carefully read and then respond. The Washington–London link was originally carried over the Transatlantic No. 1 (TAT-1), the first submarine transatlantic telephone cable, which allowed the use of teleprinters. Such a design prevented spontaneous verbal communications, which could lead to misunderstanding and misperceptions.

    First Use of the Hotline
    The hotline significantly reduced the time required for direct communication between the heads of the two governments from hours to minutes. In August 1963, the system was ready to be tested. On August 30, 1963, the United States sent its first message to the Soviet Union over the hotline: "The quick brown fox jumped over the lazy dog's back 1234567890."

    The message used every letter and number key on the teletype machine in order to see that each was in working order. The return message from Moscow was in Russian, but it indicated that all of the keys on the Soviet teletype were also functioning. After becoming operational that August, the direct communications link was tested every day.

    The United States first used the hotline when President John F. Kennedy was assassinated on November 22, 1963. The hotline was next used in June 1967 during the Six Day War between Israel, Egypt, Jordan, and Syria to clarify the intentions of U.S. fleet movements in the Mediterranean that could have been interpreted as hostile. Thereby, the Soviet Union and the United States intended to reassure each other that they did not wish to be militarily involved in the crisis and did not make efforts to bring about a ceasefire. Throughout the duration of the Six Days War, the two sides used the hotline almost two dozen times for a variety of purposes. President Richard Nixon also used it during the Indo-Pakistani War of 1971 and again during the 1973 Arab-Israeli War. During the Reagan Administration, the hotline was used several more times. However, an official listing of the instances when the states used the hotline never has been released to the public.

    Modern Version of U.S.–Russian Nuclear Hotline
    In the 1970s, the hotline was improved with better technologies. On September 30, 1971, the two sides signed the hotline modernization agreement, which updated the hotline with two satellite communications circuits. Under this agreement, the United States was to provide one circuit via the Intelsat system, and the Soviet Union was to provide one circuit via its Molniya II system. The 1963 radio circuit was terminated, and the wire telegraph was retained as a back-up. The two satellite communications circuits became operational in January 1978.

    In July 1984, the United States and the Soviet Union signed an accord to add a facsimile transmission capability to the hotline. This capability became operational in 1986.

    The two countries in September 1987 signed an agreement creating the Nuclear Risk Reduction Centers (NRRC) in both Washington and Moscow, which became operational in 1988. Though using a similar communications system, the centers are separate from the hotline. While the hotline is reserved for heads of government, the centers exchange information and notifications as required under arms control and other confidence-building agreements.

    Other Bilateral Hotline Agreements
    Once the hotline between Washington and Moscow proved to be useful, other states established hotlines. In 1966, France signed an accord establishing a direct communications link between Paris and Moscow. Under the 1967 British-Soviet agreement, a direct communications line was set up between Moscow and London.

    Russia–China Nuclear Hotline
    In 1998, China established two head-of-state nuclear hotlines, one first with Russia and another with the United States.

    In April 1996, during Russian President Boris Yeltsin’s third summit meeting in Beijing, the two sides agreed to maintain regular dialogues at various levels and through multiple channels, including a governmental telephone hotline. On May 3, 1998, a hotline between China and Russia officially began operating. This is the first time Beijing has established a hotline with the head of a foreign state. Ten years later, in March 2008, a hotline between the Chinese and Russian Defense Ministries was established to enhance bilateral cooperation between the two states. The Russian and Chinese were exchanging their views on the international and regional situation as well as other issues of common concern.

    U.S.–China Nuclear Hotline
    In April 1998, China’s Minister of Foreign Affairs Tang Jiaxuan and U.S. Secretary of State Madeleine Albright signed an agreement to establish a hotline between the governments of the two countries. The hotline was activated during President Clinton’s visit to China in June 1998.

    India–Pakistan Nuclear Hotline
    In June 2004, India and Pakistan agreed to set up a telephone nuclear hotline between the most senior officials in their foreign ministries in order to prevent a nuclear incident. The two countries also agreed to update an existing hotline between their respective directors of military operations and reaffirmed that each side would continue to uphold the moratorium on nuclear tests. A direct communications link between the two countries’ nuclear command authorities does not currently exist.

    In 2011, India and Pakistan agreed to set up a “terror hotline” so as to allow Indian investigators to visit Pakistan in connection to the 2008 Mumbai attacks. The hotline warns each party state of possible militant attacks and moves them to restore the trust between each other.

    North Korea-South Korea Hotline
    The Seoul-Pyongyang “hotline” comprises 33 telephone lines that connect North and South Korea through the Panmunjom Joint Security Area within the Demilitarized Zone. Five are used for daily communications, 21 for negotiations, and 7 for transportation and commerce.

    The first hotline, established in September 1971, was designed to allow the North and South Korean Red Crosses to negotiate. The two countries agreed to build more telephone connections in a July 4, 1972, Joint Communiqué. North Korea has periodically stopped responding to phone calls when tensions have spiked between the two countries. The most recent disconnection began in February 2016, after South Korea closed a jointly-operated manufacturing park in the Kaesong Industrial Region in response to North Korean missile testing.

    On January 3, 2018, North Korean officials responded to a phone call on a Panmunjom hotline from South Korea, breaking the two-year silence. Earlier in the day, North Korea announced the channel would be reopened, and the South’s Ministry of Unification later confirmed that they had held a 20-minute phone conversation.

    Two months later, at talks in Pyongyang on March 5, 2018, delegations from North and South Korea reached an agreement to reopen the first hotline between the presidents of each country, Kim Jong Un and Moon Jae-in. The hotline between the leaders went live on April 20, 2018.

    South Korea–China Defense Hotline
    In 2008, South Korea and China set up telephone hotlines between their navies and air forces to help prevent accidental clashes. However, the hotline has reportedly been used only a handful of times, and never to test procedures in a simulated crisis. South Korea and China agreed in July 2014 to establish an additional high-level hotline between their defense chiefs in an effort to strengthen military cooperation. The first call reportedly took place in December 2015.

    India-China Hotline
    In April 2010, the prime ministers of China and India agreed to set up a hotline between them in order to better avoid flare-ups over a longstanding border dispute across the Himalayas and strengthen their diplomatic ties. "The agreement to establish a hotline is an important confidence-building measure and it opens up a direct channel of communication between the two leaders," Nirupama Rao, India’s foreign secretary at the time, told reporters at a press conference in Beijing.

    In 2018, China and India decided to establish another hotline between their armies. India stated in January 2020 that the line would soon become operational.

    Vietnam-China Hotline
    A hotline between the Vietnamese and the Chinese Ministries of Foreign Affairs opened in March 2012. In their talk on the line, the ministers affirmed their will to strengthen the Vietnam-China comprehensive strategic cooperative partnership.

    Taiwan-China Hotline
    In November 2015, the presidents of China and Taiwan agreed to establish a hotline between their respective chiefs of cross-Strait affairs. The line became operational a month later.

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    New START at a Glance

    Contact: Shannon Bugos, Senior Policy Analyst, (202) 463-8270 x113

    Both Russia and the United States announced that they met New START limitations by Feb. 5, 2018. For more information about current nuclear forces under the treaty, see

    The New Strategic Arms Reduction Treaty (New START) was signed April 8, 2010, in Prague by the United States and Russia and entered into force on Feb. 5, 2011. New START replaced the 1991 START I treaty, which expired December 2009, and superseded the 2002 Strategic Offensive Reductions Treaty (SORT), which terminated when New START entered into force.

    New START continues the bipartisan process of verifiably reducing U.S. and Russian strategic nuclear arsenals begun by former Presidents Ronald Reagan and George H.W. Bush. New START is the first verifiable U.S.-Russian nuclear arms control treaty to take effect since START I in 1994.

    The United States and Russia agreed on Feb. 3, 2021, to extend New START by five years, as allowed by the treaty text, until Feb. 5, 2026.

    New START’s Key Provisions

    New START includes a main treaty text with a preamble and sixteen articles; a protocol with definitions, verification procedures, and agreed statements; and technical annexes to the protocol. 

    Main Treaty Limits (Article II)

    Nuclear warhead limit: Seven years after entry into force (Feb. 5, 2018), New START limits went into effect that capped accountable deployed strategic nuclear warheads and bombs at 1,550, down approximately 30 percent from the 2,200 limit set by SORT and down 74 percent from the START-accountable limit of 6,000.  Each heavy bomber is counted as one warhead (see below).

    Missile, bomber and launcher limits: Deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers assigned to nuclear missions are limited to 700. Deployed and non-deployed ICBM launchers, SLBM launchers, and bombers are limited to 800. This number includes test launchers and bombers and Trident submarines in overhaul and is approximately a 50 percent reduction from the 1,600 launcher-limit set under START (SORT did not cover launchers). The 800 ceiling is intended to limit the ability for “break out” of the treaty by preventing either side from retaining large numbers of non-deployed launchers and bombers.

    New START does not limit the number of non-deployed ICBMs and SLBMs, but it does monitor them and provide for continuous information on their locations and on-site inspections to confirm that they are not added to the deployed force. Non-deployed missiles must be located at specified facilities away from deployment sites and labeled with “unique identifiers” to reduce concerns about hidden missile stocks. Moreover, the strategic significance of non-deployed missiles is reduced given that non-deployed launchers are limited. Both sides agreed under the treaty to prohibit systems designed for “rapid reload” of non-deployed missiles (Fifth Agreed Statement).

    Force structure: Each side has the flexibility to structure its nuclear forces as it wishes, within the overall limits of the treaty.

    Counting Rules (Article III)

    Warheads: For deployed ICBMs and SLBMs, the number of warheads counted is the actual number of re-entry vehicles (RVs) on each missile (an RV protects the warhead as it re-enters the atmosphere from space; it can carry only one warhead). START I did not directly count RVs, but instead counted missiles and bombers that were “associated with” a certain number of warheads. New START counts each heavy bomber as one warhead (although the maximum loading is 16-20), the same counting rule that START I used for bombers carrying short-range weapons. Neither side typically deploys nuclear bombs or cruise missiles on bombers but keeps them in storage. Thus, inspections of bombers would find no weapons to inspect. The parties agreed to arbitrarily count each bomber as one warhead. Under SORT, Russia did not count stored bomber weapons at all. New START, like START I, does not track or limit warheads or bombs once they have been removed from deployed launchers.

    Delivery vehicles and launchers: Each deployed ICBM, SLBM, and nuclear-capable bomber is counted as one delivery vehicle against the 700 limit. Each deployed and non-deployed missile launcher or bomber is counted as one launcher against the 800 limit. Non-deployed missiles are monitored but not limited in number.

    Monitoring and Verification (Article VI, IX, X, XI, Protocol and Annexes)

    New START’s verification regime includes relevant parts of START I as well as new provisions to cover items not previously monitored. For example, the new treaty contains detailed definitions of items limited by the treaty; provisions on the use of National Technical Means (NTM); an extensive database on the numbers, types and locations of treaty-limited items and notifications about those items; and inspections to confirm this information. Even so, the verification system has been simplified to make it cheaper and easier to operate than START and to reflect new strategic realities. New START monitoring has also been designed to reflect updated treaty limitations.

    For example, the old treaty did not directly limit warheads but instead assigned a certain number of warheads to each launcher; a count of the launchers gave an upper limit on the number of warheads that could be deployed, but not necessarily an actual count. New START includes direct limits on deployed warheads and allows for on-site inspections to give both sides confidence that the limits are being upheld. Under the new treaty, both sides will exchange lists of the number of warheads deployed on individual missiles. During “Type One” inspections, each side can choose one ICBM or SLBM to inspect on short notice and count the warheads. The re-entry vehicles (RVs) can be covered by the host nation to protect sensitive information, but the actual number of RVs must be evident to the inspectors. These inspections are designed to help deter both sides from deploying a missile with more than its declared number of warheads.

    For missile-generated flight test data, known as telemetry, START I called for telemetry to be openly shared, with limited exceptions, to monitor missile development. New START does not limit new types of ballistic missiles, and thus the old START formula for extensive telemetry sharing was no longer necessary. New START requires the broadcast of telemetry and exchange of recordings and other information on up to five missile tests per side per year to promote openness and transparency.

    Under the new treaty, the United States and Russia will continue to depend on NTM to monitor the other’s strategic forces. To monitor Russian mobile ICBMs, all new missiles are subject to the treaty as soon as they leave a production facility, and each missile and bomber will carry a unique identifier. Russia must notify the United States 48 hours before a new solid-fueled ICBM or SLBM leaves the Votkinsk production facility and when it arrives at its destination, which will facilitate monitoring by national means, such as satellites. The treaty does not prohibit the modernization of strategic forces within the overall treaty limits (Article V).

    Verification of treaty limits and conversion or elimination of delivery systems is carried out by NTM and 18 annual short-notice, on-site inspections. The treaty allows ten on-site inspections of deployed warheads and deployed and non-deployed delivery systems at ICBM bases, submarine bases and air bases (“Type One” inspections). It also allows eight on-site inspections at facilities that may hold only non-deployed delivery systems (“Type Two” inspections).

    Ballistic Missile Defense (Preamble, Article V, Unilateral Statements)

    Current and planned U.S. missile defense programs are not constrained by New START. The preamble acknowledges the “interrelationship between strategic offensive arms and strategic defensive arms” and that “current strategic defensive arms do not undermine the viability and effectiveness of the strategic offensive arms of the Parties.”

    Article V prohibits both sides from converting launchers for ICBMs and SLBMs into launchers for missile defense interceptors and vice versa. This provision does not apply to five U.S. ICBM silo launchers at Vandenberg Air Force Base, in California, that were previously converted to missile defense interceptor launchers. The United States has no plans for any such conversions in the future.

    The missile defense launcher provision is designed to address Russian concerns that the United States could “break out” of New START by placing ICBMs in silos that once held missile defense interceptors. In practice, the provision will protect U.S. missile defense interceptors from falling under the treaty inspection regime. "If the parties were permitted to convert missile defense silos to ICBM silos, they would also have been able to visit and inspect those silos to confirm that they did not hold missiles limited by the treaty,” stated a report by the Congressional Research Service. The ban on silo conversions means that silo inspections are unnecessary and not permitted.

    Finally, both sides have made unilateral statements about the relationship between missile defense deployments and the treaty. These statements are not legally binding, and similar statements were issued with previous treaties, including START I. Under START, the Soviet Union said that U.S. withdrawal from the 1972 Anti-Ballistic Missile (ABM) Treaty would constitute reason for withdrawal. However, when the United States actually did withdraw from the ABM Treaty in 2002, Russia did not withdraw from START and, in fact, went on to negotiate SORT.

    Conventional Warheads (Preamble, Protocol and Annexes)

    New START does not prohibit either side from deploying conventional warheads on long-range ballistic missiles. Such deployments would be counted under the warhead and missile limitations of the treaty. The preamble states that both sides are “mindful of the impact of conventionally armed ICBMs and SLBMs on strategic stability.” The State Department stated in a report that “there is no military utility in carrying nuclear-armed and conventionally-armed reentry vehicles on the same ICBM or SLBM.”

    Trident submarines converted to carry conventional cruise missiles would not be counted under the treaty, nor would formerly nuclear-capable bombers that have been fully converted to conventional missions, such as the B-1B.

    Duration and Withdrawal (Article XIV)

    The treaty’s duration is ten years from entry into force (Feb. 2021) unless it is superseded by a subsequent agreement and can be extended for an additional five years, until 2026. As in START I, each party can withdraw if it decides for itself that “extraordinary events related to the subject matter of this treaty have jeopardized its supreme interests.” The treaty would terminate three months from a notice of withdrawal. 

    Strategic Arms Control and Policy

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    Ukraine, Nuclear Weapons, and Security Assurances at a Glance

    Contact: Daryl G. Kimball, Executive Director, (202) 463-8270 x107

    At the time of Ukraine’s independence from the Soviet Union in 1991, Ukraine held the third largest nuclear arsenal in the world, including an estimated 1,900 strategic warheads, 176 intercontinental ballistic missiles (ICBMs), and 44 strategic bombers. By 1996, Ukraine had returned all of its nuclear warheads to Russia in exchange for economic aid and security assurances, and in December 1994, Ukraine became a non-nuclear weapon state-party to the 1968 nuclear Nonproliferation Treaty (NPT). The last strategic nuclear delivery vehicle in Ukraine was eliminated in 2001 under the 1991 Strategic Arms Reduction Treaty (START). It took years of political maneuvering and diplomatic work, starting with the Lisbon Protocol in 1992, to remove the weapons and nuclear infrastructure from Ukraine.

    1990 Declaration of Sovereignty

    Partly in an effort to gain international recognition, Ukraine’s pre-independence movement supported efforts to join the NPT as a non-nuclear weapon state. With its Declaration of Sovereignty on July 16, 1990, Ukraine pledged “not to accept, produce, or acquire nuclear weapons." However, despite this public commitment, Ukrainian politicians were not entirely united by the idea. Some felt that Russia was a still a threat and that they should keep the weapons as a deterrent.

    1991 Minsk Agreement on Strategic Forces

    With the dissolution of the Soviet Union, the Commonwealth of Independent States signed the Minsk Agreement on December 30, 1991, agreeing that the Russian government would be given charge of all nuclear armaments. However, as long as the weapons remained in Belarus, Ukraine, and Kazakhstan, the governments of those countries would have the right to veto their use. The target date for dismantling the weapons was set for the end of 1994.

    1992 Lisbon Protocol

    Ukraine signed the Lisbon Protocol on May 23, 1992. The protocol sought to return the nuclear weapons in Belarus, Kazakhstan, and Ukraine to Russia. All states were to join START and the NPT. However, within Ukraine, there was little motion towards the ratification of START, joining the NPT, or overall denuclearization. The protocol required that Ukraine adhere to the NPT as quickly as possible, but it gave the country up to seven years to follow through.

    By late 1992, the Ukrainian parliament was vocalizing more pro-nuclear views. Some believed that Ukraine was entitled to at least temporary nuclear weapon status. Perhaps optimistically, the U.S. government promised Ukraine $175 million in dismantlement assistance. Instead, the Ukrainian government began implementing administrative management of the nuclear forces and claimed ownership of the warheads.

    In late April 1993, 162 Ukrainian politicians signed a statement to add 13 preconditions for ratification of START, frustrating the ratification process. The preconditions required security assurances from Russia and the United States, foreign aid for dismantlement, and compensation for the nuclear material. Additionally, they stated that Ukraine would dismantle only 36 percent of its delivery vehicles and 42 percent of its warheads, leaving the rest under Ukrainian control. Russia and the United States criticized these demands, but Ukraine did not budge. In May 1993, the United States said that if Ukraine were to ratify START, Washington would provide more financial assistance. This began subsequent discussions between Ukraine, Russia, and the United States over the future of Ukrainian denuclearization.

    1993 Massandra Accords

    Ukrainian and Russian officials reached a set of agreements, including protocols on nuclear weapons dismantlement, procedure, and terms of compensation. However, the two sides could not agree on the final document, and the summit ultimately failed. 

    1994 Trilateral Statement

    The Massandra Accords set the stage for the ultimately successful trilateral talks. As the United States mediated between Russia and Ukraine, the three countries signed the Trilateral Statement on January 14, 1994. Ukraine committed to full disarmament, including strategic weapons, in exchange for economic support and security assurances from the United States and Russia. Ukraine agreed to transfer its nuclear warheads to Russia and accepted U.S. assistance in dismantling missiles, bombers, and nuclear infrastructure. Ukraine’s warheads would be dismantled in Russia, and Ukraine would receive compensation for the commercial value of the highly enriched uranium. Ukraine ratified START on February 3, 1994, repealing its earlier preconditions, but it would not accede to the NPT without further security assurances.

    1994 Budapest Memorandum on Security Assurances

    To solidify security commitments to Ukraine, the United States, Russia, and the United Kingdom signed the Budapest Memorandum on Security Assurances on December 5, 1994. A political agreement in accordance with the principles of the Helsinki Accords, the memorandum included security assurances against the threat or use of force against Ukraine’s territory or political independence. The countries promised to respect the sovereignty and existing borders of Ukraine. Parallel memorandums were signed for Belarus and Kazakhstan as well. In response, Ukraine officially acceded to the NPT as a non-nuclear weapon state on December 5, 1994. That move met the final condition for ratification of START, and on the same day, the five START states-parties exchanged instruments of ratification, bringing the treaty into force.

    2009 Joint Declaration by Russia and the United States

    Russia and the United States released a joint statement in 2009 confirming that the security assurances made in the 1994 Budapest Memorandum would still be valid after START expired in 2009.

    2014 Russian Annexation of Crimea

    Following months of political unrest and the abrupt departure of Ukrainian President Viktor Yanukovych, Russian troops entered the Crimean peninsula of Ukraine in March 2014. On March 18, over the protests of the acting government in Kiev, the UN Security Council, and Western governments, Russia declared the annexation of Crimea. The United States, the United Kingdom, and Ukraine called the action a blatant violation of the security assurances in the 1994 Budapest Memorandum. However, according to the Russian Foreign Ministry, “the security assurances were given to the legitimate government of Ukraine but not to the forces that came to power following the coup d'etat.”


    • July 16, 1990: Ukraine’s Declaration of Sovereignty
    • July 31, 1991: The United States and the Soviet Union sign START
    • Dec. 26, 1991: The Soviet Union officially dissolves, delaying entry into force of START
    • Dec. 30, 1991: Minsk Agreement on Strategic Forces
      • The Commonwealth of Independent States agrees that strategic forces would be under the joint command of the former Soviet Union states
    • May 23, 1992: Russia, Belarus, Ukraine, Kazakhstan, and the United States sign the Lisbon Protocol
      • The protocol calls for the return of nuclear weapons in three formerly Soviet states to Russia and for all states to be added to the START treaty and join the NPT
    • Jan. 14, 1994: Ukraine, Russia, and the United States sign the Trilateral Statement
      • Ukraine commits to full disarmament, including strategic offensive weapons, in exchange for economic support and security assurances from the United States and Russia
    • Sept. 4, 1993: Massandra Accords
      • Failed summit between Russian and Ukrainian governments
    • Dec. 5, 1994: Russia, Ukraine, United States, and the United Kingdom sign the Budapest Memorandum on Security Assurances
      • Includes security assurances against the threat or use of force against Ukraine’s territory or political independence
    • Dec. 5, 1994: Ukraine submits its instrument of accession to the NPT as a non-nuclear weapon state
      • The five START parties exchange instruments of ratification for START, which enters into force
    • June 1, 1996: Ukraine transfers its last nuclear warhead to Russia
    • October 30, 2001: Ukraine eliminates its last strategic nuclear weapon delivery vehicle
    • Dec. 4, 2009: Joint Statement by Russia and the United States
      • The two countries confirm the security guarantees made in the 1994 Budapest Memorandum
    • March 18, 2014: Russia annexes Ukraine's Crimean peninsula and provides supports an ongoing insurrection by separatist forces in the eastern Luhansk and Donetsk provinces of Ukraine.
    • Late 2021 to early 2022: Russia engages in "military exercises" with a force estimated to exceed 150,000 military personnel involving land-, sea-, and air-based weaponry on the northern, eastern, and southern borders of Ukraine raising fears of an invasion by Russia.
    • February 24, 2022: Russia began a large-scale military attack and invasion of Ukraine, with planes and missile launcher attacks on Ukrainian cities, airports, and military infrastructure across much of the country.
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    START I at a Glance

    Contacts: Daryl Kimball, Executive Director, (202) 463-8270 x107

    The Strategic Arms Reduction Treaty (START) I was signed July 31, 1991, by the United States and the Soviet Union. This was the first treaty that required U.S. and Soviet/Russian reductions of strategic nuclear weapons. It was indispensable in creating a framework that ensured predictability and stability for deep reductions.

    In December 1991, the Soviet Union dissolved, leaving four independent states in possession of strategic nuclear weapons: Russia, Belarus, Ukraine, and Kazakhstan. This caused a delay in the entry into force of the treaty. On May 23, 1992, the United States and the four nuclear-capable successor states to the Soviet Union signed the Lisbon Protocol, which made all five nations party to the START I agreement. 

    START I entered into force Dec. 5, 1994, when the five treaty parties exchanged instruments of ratification in Budapest. 

    Reductions of nuclear weapons were completed by the deadline of December 5, 2001, seven years after entry into force, and maintained for another eight years. States were verified by on-site inspections and shared missile telemetry. Both the United States and the Russian Federation continued reduction efforts even after reaching the START limits. 

    START I expired on Dec. 5, 2009. The United States and Russia signed START II in January 1993, but the treaty never entered into force. The 2002 Strategic Offensive Reduction Treaty (SORT, or the Moscow Treaty) entered into force in 2003, followed by the 2010 New Strategic Arms Reduction Treaty (New START) in 2011.

    Basic Terms:

    • 1,600 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy (long-range) bombers for each side, including 154 deployed heavy ICBMs (only the Soviet Union possessed the latter type of missile, the SS-18 Satan)
    • 6,000 "accountable" warheads on ICBMs, SLBMs, and heavy bombers, of which no more than 4,900 may be on ICBMs and SLBMs, 1,540 on heavy ICBMs, and 1,100 on mobile ICBMs (the latter limitation essentially applied only to the Soviet Union with missiles such as the RS-12M Topol as the United States chose not to deploy such missiles after the treaty’s signing)
    • Limited ballistic missile throw-weight (lifting power) to 3,600 metric tons on each side

    Counting Rules:

    • Each reentry vehicle of an ICBM or an SLBM counts as a single warhead.
    • Heavy bombers equipped only with bombs or short-range attack missiles (SRAMs) are counted as carrying one warhead each.
    • U.S. heavy bombers may carry no more than 20 long-range air-launched cruise missiles (ALCMs) each. The first 150 of these bombers count as carrying only 10 ALCMs each.
    • Soviet heavy bombers may carry no more than 16 ALCMs each. The first 180 of these bombers count as carrying only eight ALCMs each.
    • No more than 1,250 warheads may be "downloaded" (removed from) and not counted on existing multiple-warhead ballistic missiles.

    Inspections and Verification Protocols:

    • The treaty allows for the use of National Technical Means (NTMs) of verification and prohibits any interference with one another’s NTMs.
    • Accompanying the treaty is a Memorandum of Understanding (MOU), which contains data on the numbers and locations of all (deployed and non-deployed) strategic delivery vehicles, plus the locations and diagrams of all facilities associated with strategic delivery vehicles, such as bases and storage and production facilities. The two parties must exchange the entire set of data contained in the memorandum every six months. Each party must notify the other if there is any change in that data shortly after that change occurs.
    • The treaty allows for on-site inspections, both short-notice and planned, and continuous monitoring activities in order to verify the data contained in the memorandum. During the first seven years of START, the United States conducted 335 inspections, and Russia conducted 243.
    • The treaty permits perimeter and portal monitoring of plants for mobile ICBMs. The United States did not deploy such missiles, so these measures applied only to Russia. (The 1987 Intermediate-Range Nuclear Forces Treaty had already permitted U.S. monitoring of these missiles.)
    • The treaty banned any encryption or jamming of telemetry transmitted from ballistic missiles during test launches.

    Other Provisions:

    • START I ran for 15 years with an option to extend for successive five-year periods unless superseded by another agreement. Based on commitments made at the March 1997 Helsinki Summit, the sides agreed in principle to negotiate an agreement making the START treaties unlimited in duration.
    • Separate "politically binding" agreements limit the number of deployed nuclear sea-launched cruise missiles with ranges above 600 kilometers to 880 for each side and the number of Soviet Tu-22M Backfire (Tupolev) medium bombers to 500, including no more than 200 naval Tu-22M bombers.
    Strategic Arms Control and Policy

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