START I

Press Contact: Daryl Kimball, Executive Director, (202) 463-8270 x107; Tom Z. Collina, Research Director; (202) 463-8270 x104

Over the past four decades, American 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

SALT I
Begun in November 1969, the Strategic Arms Limitation Talks (SALT) produced by May 1972 both the Anti-Ballistic Missile (ABM) Treaty, which limited strategic missile defenses to 200 (later 100) interceptors each, and the Interim Agreement, an executive agreement that capped U.S. and Soviet ICBM and SLBM forces. Under the Interim Agreement, both sides pledged not to construct new ICBM silos, not to increase the size of existing ICBM silos “significantly,” and capped the number of SLBM launch tubes and SLBM-carrying submarines. The agreement ignored strategic bombers and did not address warhead numbers, leaving both sides free to enlarge their forces by deploying multiple warheads (MIRVs) onto their ICBMs and SLBMs and increasing their bomber-based forces. The agreement limited the United States to 1,054 ICBM silos and 656 SLBM launch tubes. The Soviet Union was limited to 1,607 ICBM silos and 740 SLBM launch tubes. In January 2002, the United States unilaterally withdrew from the ABM treaty.

SALT II
In November 1972, Washington and Moscow agreed to pursue a follow-on treaty to SALT I. SALT II, signed in June 1979, 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. However, 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, on May 26, 1986, President Ronald Reagan said 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.”

START I
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 ensuing efforts to denuclearize Ukraine, Kazakhstan, and Belarus by returning their nuclear weapons to Russia and making them parties to the NPT and START agreements.  START I reductions were completed in December 2001 and the treaty expired on Dec. 5, 2009.

START II
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 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…to promote the irreversibility of deep reductions including prevention of a rapid increase in the number of warheads.” Negotiations were supposed to begin after START II entered into force, which never happened.

SORT
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 are reducing their strategic arsenals to 1,700-2,200 warheads each. The warhead limit takes effect and expires on the same day, December 31, 2012. Although the two sides have not agreed on specific counting rules, the Bush administration had asserted that the United States would reduce only warheads deployed on strategic delivery vehicles in active service, i.e., “operationally deployed” warheads, and will 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 does 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 February 5, 2011.

New START
On April 8, 2010, the United States and Russia signed New START, a legally binding, verifiable agreement that limits each side’s deployed strategic nuclear warheads to 1,550 and strategic delivery systems (ICBMs, SLBMs and heavy bombers) to 800 deployed and nondeployed, such as submarines in overhaul, with a sublimit of 700 deployed. 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 year) and does not meaningfully limit missile defenses or long-range conventional strike capabilities. The treaty limits take effect seven years after entry into force, and the treaty will be in effect for 10 years, or longer if agreed by both parties. 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 January 26, 2011. The treaty entered into force on February 5, 2011.

Strategic Nuclear Arms Control Agreements

Nonstrategic Nuclear Arms Control Measures

Intermediate-Range Nuclear Forces (INF) Treaty
Signed December 8, 1987, the 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 current active participants in the agreement include the United States, Russia, Belarus, Kazakhstan, and Ukraine. Turkmenistan and Uzbekistan are also parties to the agreement but do not participate in treaty meetings or on-site inspections. The ban on intermediate-range missiles is of unlimited duration.

Presidential Nuclear Initiatives
On September 27, 1991, President George H. W. Bush announced that the United States would remove almost all U.S. tactical 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 its nuclear artillery shells and short-range nuclear ballistic missile warheads and remove all nonstrategic nuclear warheads from surface ships, attack submarines, and land-based naval aircraft. Soviet leader Mikhail Gorbachev reciprocated on October 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. 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.

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

START I was signed July 31, 1991, by the United States and the Soviet Union. Five months later, the Soviet Union dissolved, leaving four independent states in possession of strategic nuclear weapons: Russia, Belarus, Ukraine, and Kazakhstan. On May 23, 1992, the United States and the four nuclear-capable successor states to the Soviet Union signed the "Lisbon Protocol," which makes all five nations party to the START I agreement. START I entered into force December 5, 1994, when the five treaty parties exchanged instruments of ratification in Budapest. All treaty parties met the agreement's December 5, 2001 implementation deadline. START is due to expire on December 5, 2009, though the parties may agree to extend it for another five years or until it is superseded by another arms reduction agreement.

Basic Terms:

• 1,600 deployed intercontinental ballistic missiles (ICBMs), submarine-launched ballistic missiles (SLBMs), and heavy bombers for each side.
• 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 missiles (the Soviet SS-18), and 1,100 on mobile ICBMs.
• Ballistic missile throw-weight (lifting power) is limited to 3,600 metric tons on each side.

Counting Rules:

• 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.

Other Provisions:

• START I runs for 15 years with an option to extend for successive five-year periods. 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 sea-launched cruise missiles with ranges above 600 kilometers to 880 for each side and the Soviet Backfire bomber to 500.

Press Contact: Tom Collina, Research Director; (202) 463-8270 x104

A pervasive fear surrounding the collapse of the Soviet Union was the uncertain fate of its nuclear arsenal. In addition to Russia, the emerging states of Belarus, Kazakhstan, and Ukraine, inherited a significant number of nuclear weapons, raising concerns that the Soviet Union would leave four nuclear weapon successor states instead of just one. Aside from increasing the number of governments with their finger on the proverbial nuclear button, the circumstances simultaneously raised concerns that those weapons might be more vulnerable to possible sale or theft. The Lisbon Protocol, concluded on May 23, 1992, sought to alleviate those fears by committing the three non-Russian former Soviet states to return their nuclear weapons to Russia. In spite of a series of political disputes that raised some concerns about implementation of the protocol, all Soviet nuclear weapons were eventually transferred to Russia by the end of 1996.

When the Soviet Union officially dissolved in December 1991, the newly-independent states of Belarus, Kazakhstan, and Ukraine inherited more than 3,000 strategic nuclear weapons (those capable of striking the continental United States), as well as at least 3,000 tactical or battlefield nuclear weapons. All dispersed Soviet tactical weapons were reportedly back on Russian soil by the end of 1992, but the strategic weapons posed a larger problem.<!--[if !supportFootnotes]-->[1]<!--[endif]--> The United States and Russia reached a solution to this complex problem by engaging Belarus, Kazakhstan, and Ukraine in a series of talks that led to the Lisbon Protocol. That agreement made all five states party to the 1991 Strategic Arms Reduction Treaty (START), which required Washington and Moscow to each cut their deployed strategic nuclear forces from approximately 10,000 warheads apiece to down below 6,000 warheads on no more than 1,600 ICBMs, submarine-launched ballistic missiles (SLBM), and long-range bombers. The protocol signaled the intentions of Belarus, Kazakhstan, and Ukraine to forswear nuclear arms and accede to the nuclear Nonproliferation Treaty (NPT) as non-nuclear-weapon states, a commitment that all three fulfilled and continue to abide by today.

Estimated Warheads in Belarus, Kazakhstan, and Ukraine in 1991

Sources: Robert S. Norris, “The Soviet Nuclear Archipelago,” Arms Control Today, January/February 1992, p. 24 and Joseph Cirincione, et al., Deadly Arsenals, Carnegie Endowment for International Peace, 2005, p. 366.

Basic Timeline and Provisions:

• July 31, 1991: The United States and the Soviet Union sign START.
• Dec. 31, 1991: The Soviet Union officially dissolves, delaying entry into force of START.
• May 23, 1992: Russia, Belarus, Ukraine, Kazakhstan, and the United States sign the Lisbon Protocol.
  • Under the protocol, all five states become parties to START.
  • Belarus, Kazakhstan, and Ukraine promise to accede to the NPT as non-nuclear-weapon states “in the shortest time possible.”
• July 2, 1992: Kazakhstan ratifies START.
• Oct. 1, 1992: The U.S. Senate ratifies START.
• Nov. 4, 1992: The Russian State Duma refuses to exchange START instruments of ratification until Belarus, Ukraine, and Kazakhstan accede to the NPT.
• Feb. 4, 1993: Belarus ratifies START.
• July 22, 1993: Belarus submits its instrument of accession to the NPT as a non-nuclear-weapon state.
• January 14, 1994: The Trilateral Statement is signed by Presidents Clinton, Yeltsin, and Leonid Kravchuk of Ukraine, allowing Ukraine to observe the transfer of weapons from its territory to Russia and the dismantlement of certain systems. It also commits Russia to send some of the uranium extracted from the returned warheads back to Ukraine for fuel.
• Feb. 14, 1994: Kazakhstan submits its instrument of accession to the NPT as a non-nuclear-weapon state.
• 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.
• April 24, 1995: Kazakhstan transfers its last strategic weapon to Russia.
• June 1996: Ukraine transfers its last strategic weapon to Russia.
• November 1996: Belarus transfers its last strategic weapon to Russia, marking completion of Lisbon Protocol obligations.

Ratification and Implementation:

Belarus:

When the Soviet Union dissolved, the newly-established Republic of Belarus found itself in possession of roughly 800 total nuclear weapons deployed within its borders. Although Russia retained the warhead arming and launch codes, many worried that Belarus might attempt to take control of the weapons. Moreover, President Alexander Lukashenko twice threatened to retain some weapons if NATO deployed nuclear weapons of its own in Poland. However, when a constitutional crisis erupted in November 1996, Lukashenko was finally compelled to finalize the transfers.

Minsk signed the Lisbon Protocol on May 23, 1992, ratified it on Feb. 4, 1993, and deposited its instrument of accession to the NPT as a non-nuclear-weapon state on July 22, 1993. By November 1996 all nuclear warheads in Belarus had been transferred to Russia.

Kazakhstan:

After gaining independence, Kazakhstan with extensive U.S. technical and financial assistance disposed of the strategic nuclear weapons that it inherited from the Soviet Union. Kazakhstan’s 1,410 strategic warheads were deployed on several different systems, including SS-18 ICBMs and cruise missiles carried by Bear-H bombers.

Kazakhstan’s parliament ratified START on July 2, 1992. All tactical nuclear weapons had been withdrawn to Russia by January 1992. The parliament approved accession to the NPT on Dec. 13, 1993, and deposited the state’s NPT instrument of ratification on Feb. 14, 1994. The last of the Kazakh-based strategic nuclear weapons were transferred to Russia by April 24, 1995.

Ukraine:

When the Soviet Union dissolved, Ukraine became the third-largest nuclear weapons power in the world behind the United States and Russia. Ukraine’s 1,900 strategic warheads were distributed among ICBMs, strategic bombers, and air-launched cruise and air-to-surface missiles. Although President Leonid Kravchuk signed the Lisbon Protocol on May 23, 1992, Ukraine’s process of disarmament was filled with political obstacles. Many Ukrainian officials viewed Russia as a threat and argued that they should keep nuclear weapons in order to deter any possible encroachment from their eastern neighbor. Although the government never gained operational control over the weapons, it declared “administrative control” in June 1992, and, in 1993, claimed ownership of the warheads, citing the potential of the plutonium and highly enriched uranium they contained for creating peaceful energy.

A resolution passed by the Rada, the Ukrainian parliament, on Nov. 18, 1993, attached conditions to its ratification of START that Russia and the United States deemed unacceptable. Those stated that Ukraine would only dismantle 36% of its delivery vehicles and 42% of its warheads; all others would remain under Ukrainian custody. Moreover, the resolution made those reductions contingent upon assurances from Russia and the United States to never use nuclear weapons against Ukraine (referred to as “security assurances”), along with foreign aid to pay for dismantlement.

In response, the Clinton and Yeltsin administrations intensified negotiations with Kyiv, eventually producing the Trilateral Statement, which was signed on Jan. 14, 1994. This agreement placated Ukrainian concerns by allowing Ukraine to cooperate in the transfer of the weapons to Russia, which would take place over a maximum period of seven years. The agreement further called for the transferred warheads to be dismantled and the highly enriched uranium they contained to be downblended into low-enriched uranium. Some of that material would then be transferred back to Ukraine for use as nuclear reactor fuel. Meanwhile, the United States would give Ukraine economic and technical aid to cover its dismantlement costs. Finally, the United States and Russia responded to Ukraine’s security concerns by agreeing to provide security assurances upon its NPT accession.

In turn, the Rada ratified START, implicitly endorsing the Trilateral Statement. However, it did not submit its instrument of accession to the NPT until Dec. 5, 1994, when Russia, the United Kingdom, France, and the United States provided security assurances to Ukraine. That decision by the Rada met the final condition for Russia’s ratification of START, and subsequently brought that treaty into force.