Nuclear Modernization in an Age of Austerity

Amy F. Woolf

When Secretary of Defense Chuck Hagel spoke about U.S. nuclear forces at F.E. Warren Air Force Base in early January, he emphasized two key points. First, he declared that the United States was “going to invest in the modernization we need to invest in to keep that deterrent stronger than it’s ever been.”

He then added that “we’re going to continue to require every element of our nuclear deterrent in the triad.”[1] His audience at the Wyoming base might have heard a welcome, if unexceptional, commitment to the future of the U.S. nuclear deterrent, but there could have been more to the secretary’s comments. In this period of fiscal constraints and declining defense budgets, many in in the wider policy community are voicing doubts about the ability of the United not only to maintain all three legs of the nuclear triad, but also to replace each leg with new missiles, bombers, and submarines.

Although the current debate over the future composition of the U.S. nuclear arsenal often is framed in fiscal terms, it is more about the future need for and role of nuclear weapons than it is about how much money the U.S. government is going to spend on them. Critics of the current plans to modernize the U.S. nuclear force structure argue that the investments are excessive because nuclear weapons are less relevant to U.S. national security in the 21st century than they were in the past. Supporters argue that this investment is necessary because nuclear weapons continue to play a critical role in U.S. national security. Regardless, if defense budgets continue to decline in the coming decades, the country may face difficult and possibly illogical trade-offs as it pays for the rising cost of nuclear modernization.

The United States deploys strategic nuclear warheads on three types of delivery vehicles: long-range, land-based intercontinental ballistic missiles (ICBMs), long-range submarine-launched ballistic missiles (SLBMs), and long-range heavy bombers based in the United States. Each of the delivery systems in the U.S. nuclear force is aging, and all could reach the end of their service lives in the next 30 years. The warheads that these systems would deliver also are more than 25 years old and contain aging components that may raise questions about their reliability in the future.

The U.S. Navy and Air Force are pursuing programs to modernize and replace all U.S. nuclear delivery systems—the submarines, missiles, and bombers—while the Department of Energy plans to refurbish the nuclear warheads carried by those delivery systems. Hagel has acknowledged that pursuing these modernization programs in an age of austerity “would require setting priorities and minding the budget,” but he failed to mention how much money this might cost or to acknowledge any of the difficult choices the Pentagon and nation might face.

These programs represent a commitment to rebuild and recapitalize the entire U.S. nuclear arsenal so that the country can retain a triad like the one it has today for another 50 years. This long-term plan seems ready to proceed regardless of whether the fiscal environment will support it and the security environment will require it.

Supporting the Triad

The United States has deployed its strategic nuclear warheads on three types of delivery systems since the early 1960s. Although bureaucratic politics and interservice competition for budget share played a role in shaping the U.S. force and creating the triad, each leg brought strengths and weaknesses into the U.S. nuclear deterrent during the Cold War. Taken together, the three legs were thought to complicate Soviet attack planning by ensuring that after absorbing a Soviet first strike, the United States would have a surviving arsenal large enough to retaliate with devastating force.

The United States continued to maintain the triad as it reduced the numbers of its nuclear weapons in the 1990s. In discussions about the triad, the Department of Defense often cited the deterrent value of the synergy among the three legs, but also emphasized that this force structure provided a hedge against unexpected problems in any single delivery system. This characteristic grew in importance as the United States retired many of the different types of warheads and missiles it had deployed over the years.

Although today’s security threats differ from those of the Cold War, supporters argue that the legs of the triad still have complementary capabilities that can contribute to a stable and robust deterrent. Moreover, they contend, by maintaining diversity across the force, each leg can still serve as a hedge against technical problems that may arise in the other legs. Others, however, argue that this synergy and diversity is no longer necessary, as the United States could deter emerging and potential threats with fewer types and numbers of nuclear weapons.

The Obama administration has cited both synergy and diversity as reasons to support the triad. In the 2010 “Nuclear Posture Review [NPR] Report,” it noted that ballistic missile submarines (SSBNs) and the missiles they carry “represent the most survivable leg of the U.S. nuclear Triad…. Single-warhead ICBMs contribute to stability, and like SLBMs are not vulnerable to air defenses. Unlike ICBMs and SLBMs, bombers can be visibly deployed forward, as a signal in crisis to strengthen deterrence of potential adversaries and assurance of allies and partners.” The NPR Report also emphasized that the retention of “sufficient force structure in each leg” would allow the United States “the ability to hedge effectively by shifting weight from one Triad leg to another if necessary due to unexpected technological problems or operational vulnerabilities.”[2]

The analysis in the NPR Report shaped the negotiations on the 2010 New Strategic Arms Reduction Treaty (New START). As a result, the treaty was crafted so that the United States could retain its triad while reducing its deployed forces to the treaty’s limit of 1,550 warheads. In a follow-on study completed in mid-2013, the Obama administration decided that the United States could meet its nuclear targeting requirements with one-third fewer warheads, a point the White House emphasized in a June 2013 summary of the study’s results.[3] Even if it implements this reduction, however, the United States would likely continue to deploy a triad. The report to Congress summarizing the study stated that “retaining all three legs of the triad will best maintain strategic stability at reasonable cost, while hedging against technical problems or vulnerabilities.”[4]

Hence, it appears that the administration’s commitment to the triad is unwavering. Many in Congress also have pledged their support. In the fiscal year 2014 National Defense Authorization Act, Congress specified that the Pentagon could not spend any money provided for fiscal year 2014 to “reduce, convert, or decommission any strategic delivery system if such reduction, conversion, or decommissioning would eliminate a leg of the nuclear triad.”[5]

Current Forces and Modernization

Current U.S. forces and the planned modernization efforts for each of the three legs of the triad are summarized below.[6]

Ballistic missile submarines. The Ohio-class (Trident) SSBNs first entered the Navy’s fleet in 1981, with the last of 18 submarines beginning service in 1997. The Navy has converted four submarines to carry cruise missiles, and two are usually in overhaul, so the Navy operates 12 submarines equipped with Trident-2 (D-5) nuclear-armed ballistic missiles. Seven are based at Naval Base Kitsap in Washington state, and five are based at Naval Submarine Base Kings Bay in Georgia. The Navy will retain 12 operational submarines under New START, although it will reduce the number of launchers on each from 24 to 20. These submarines can remain in service for 42 years, so they will begin to retire in 2027.

The Navy is designing a new class of SSBNs to replace the aging Ohio-class boats. It had initially planned to begin deployment in 2029, but it delayed the program by two years in the fiscal year 2013 budget. As a result, the number of SSBNs in the fleet will decline to 10 for most of the 2030s. With an expected 40-year life span, these submarines would remain in the U.S. fleet through the 2075-2080 time frame. The Congressional Budget Office (CBO) has estimated that the acquisition program for the new SSBN could cost $97-102 billion, with $10-15 billion for research and development (R&D) and $87 billion for the procurement of 12 submarines.[7]

Aircraft and cruise missiles. The Air Force currently has 20 B-2 bombers and 76 B-52 bombers. It plans to keep a maximum of 60 bombers under New START. The B-2 bombers are based at Whiteman Air Force Base in Missouri while the B-52s are located at Barksdale Air Force Base in Louisiana and Minot Air Force Base in North Dakota. The B-2 bombers first entered the fleet in 1997; the Air Force expects them to remain active until 2034 or later. The B-2 bomber can carry B61 and B83 nuclear bombs. The B-52 bomber first entered service in 1961 and is expected to remain in the fleet through 2040. The B-52 bombers can carry nuclear or conventional cruise missiles and several other conventional weapons.

The Air Force has initiated a life extension program (LEP) for the nuclear-armed cruise missile and plans to sustain this system through 2030. It is also pursuing the development of an advanced, long-range, standoff cruise missile that will replace the existing cruise missile after 2030. Although the Air Force has not released data on the total cost of this system, current budget documents indicate that it will spend $1 billion on R&D through 2018.

The Air Force also plans to develop a new bomber, primarily to conduct long-range conventional missions in areas where adversaries are expected to operate sophisticated air defense systems. The Air Force plans to procure 80-100 bombers, with the first expected to enter service around 2025 at an estimated procurement cost of $550 million for each bomber, and to equip the bomber with nuclear weapons as B-52 and B-2 bombers retire from the fleet.

Land-based ballistic missiles. The Air Force first deployed Minuteman III ICBMs in 1970. It currently deploys 450 of these missiles, with 150 missiles at each of three bases, in North Dakota, Wyoming, and Montana. Under New START, the Air Force will likely retain 400-420 ICBMs at those three bases, with each missile carrying a single warhead. The Air Force has recently upgraded the missiles so that they can remain in service through 2030 and is studying options for a follow-on missile for deployment after 2030. If it decides to buy a new missile, procurement could begin in the mid-2020s and would overlap with the Navy’s new SSBN program and the Air Force’s new heavy bomber program. As an alternative, the Air Force could decide to continue to invest in programs that would sustain and maintain the existing Minuteman III ICBMs.

Warhead Modernization

The United States currently has seven different types of nuclear warheads in its active stockpile. These include two types of warheads for land-based missiles, two for sea-based missiles, two for air-dropped bombs, and one for air-delivered cruise missiles. The Energy Department has indicated that it is likely to retire the B83 bomb in the mid-2020s, but the rest of the warheads will need to undergo LEPs to remain in the force into the future. The LEP for the W76 SLBM warhead is nearing completion, while the program for the B61 bomb is just beginning.

That program will replace aging components and add a guided tail kit to improve the accuracy of the B61. It has proven controversial in recent years, in part because its costs have escalated. The Energy Department plans to modify around 400 bombs at a cost of around $11 billion over the next 10 years.

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This is just one piece of a life extension and warhead modification effort that could total $60 billion over 25 years. Moreover, as the Energy Department pursues these LEPs, it plans to consolidate the warhead stockpile by creating warheads that can operate on land- or sea-based missiles. After implementing this plan, the United States would have five types of warheads instead of the current seven, with three types of warheads for ICBMs and SLBMs and two types for bombers—the B61 gravity bomb and a cruise missile warhead.

The Cost of Nuclear Weapons

There is no single, authoritative estimate of the amount of money that the United States will spend to operate and maintain the current force of nuclear warheads and delivery systems or to complete all the planned modernization programs. In 2010, when the Obama administration first outlined its plan, it estimated that the Defense and Energy departments would spend around $210 billion between 2010 and 2020 (in 2010 dollars), but this did not include most of the costs of modernizing the arsenal because those fell outside the time frame. In December 2013, the CBO calculated that the United States would spend approximately $241 billion on a similar set of activities between 2014 and 2023; it added $56 billion for command, control, and communications systems and $59 billion to cover anticipated cost growth in planned programs.[8] Around $89 billion of the CBO’s $355 billion total would go to the modernization programs, but, as with the administration’s estimate, this does not include the modernization costs that would occur after 2023. Nevertheless, the CBO noted that annual spending on nuclear weapons would rise from $18 billion in 2014 to an average of $29 billion from 2021 to 2023 and that spending was “likely to continue to grow after 2023 as production begins on replacement systems.”

In a briefing prepared in May 2013, the Air Force estimated that the investments in nuclear modernization programs would peak between 2025 and 2035 at approximately $30 billion per year.[9] In January, a study published by the James Martin Center for Nonproliferation Studies estimated that the United States would spend nearly $1 trillion over the next 30 years, or an average of more than $30 billion per year, to maintain and modernize the triad.[10] Hence, it seems that although each of these studies used different methodologies, they all conclude that the United States may spend at least $30 billion per year to fund its program for maintaining and replacing nuclear warheads and delivery systems.

After the release of the CBO study, some analysts referred to the spending identified in the report as “astronomical” and “bloated” and argued that the United States could cut the programs to reduce the costs without undermining U.S. security. Others argued that the investment identified by CBO was “negligible” because nuclear weapons are essential for U.S. national security.[11] These authors reached different conclusions about whether United States can afford its nuclear weapons programs because they hold different views about the value of nuclear weapons in U.S. national security policy. They differ in their assessments of the numbers and types of nuclear weapons the United States will need to deter its adversaries and assure its allies of its commitment to their security. Yet, even those who place a high value on nuclear weapons ought to ask whether the United States can afford to allocate nearly $1 trillion to nuclear weapons modernization over the next few decades.

Modernization and Austerity

In late 2011, less than a year after the Obama administration outlined its plan to modernize the U.S. nuclear enterprise, Congress passed the Budget Control Act. Under this law, the budgets projected for the Pentagon would be $60-90 billion lower per year than those expected before the law’s passage. In other words, the Pentagon could have nearly $1 trillion less to spend over the 10 years covered by the nuclear modernization plans outlined in 2010.

This reduction will cut into force structure and operations across the U.S. military. Yet, the Air Force and Navy still plan to pursue nuclear modernization programs that will increase spending from today’s $18 billion to more than $30 billion per year. If these plans do not change, they could force unpleasant trade-offs and illogical outcomes. For example, Navy officials have stated that the Navy will have to forgo 32 new ships in the next 30 years to pay for 12 new ballistic missile submarines and stay within the current shipbuilding budget. Rear Admiral Richard Breckenridge, the director of the Navy’s Undersea Warfare Division, suggested that the Navy could solve this dilemma if the other services contributed $4 billion per year to the Navy’s shipbuilding budget for 15 years.

Without this added funding, the Navy might end up with fewer submarines, leaving it unable to meet the requirements established by the current nuclear weapons employment guidance. In other words, if the Army and Air Force do not reduce their forces to help pay for the next generation of ballistic missile submarines, budget reductions could force the United States to alter its nuclear posture regardless of its professed plans and policies.

The Air Force might face similar dilemmas because it plans to purchase a new bomber, a new cruise missile for that bomber, and a new land-based ballistic missile, all at around the same time. If it cannot afford two new missiles and it sets its priorities on maintaining the land-based leg of the triad, then the Air Force may cancel the new cruise missile. Without the cruise missile, the B61 bomb would be the only weapon keeping bombers in the triad. Yet, the rising cost of the LEP for the B61 bomb might undermine support for that program. With neither a new cruise missile nor a modified B61 bomb to carry, the bombers would have no role to play in the nuclear mission. Conversely, if the Air Force buys the cruise missile and the Energy Department refurbishes the B61 bomb, the Air Force may not be able to afford new land-based missiles. It could continue to replace aging parts on its existing ICBMs, but eventually the land-based leg of the triad may be beyond repair. In either case, budget constraints would force the U.S. triad to become a dyad, regardless of any stated commitment to sustain all three legs.

It seems unlikely that spending on nuclear weapons will grow at a rate needed to support the full scope of the modernization plans. Moreover, it is difficult to imagine increased Pentagon spending on nuclear weapons at the expense of conventional forces and capabilities. Thus, the services can stay their course until budget realities force irrational changes in their plans, or they can change their plans so that the outcome is affordable and consistent with U.S. national security needs. This latter option, however, could require a restructuring of U.S. nuclear policy and a reconsideration of the future nuclear force. In other words, the United States will need to think now about altering the role of nuclear weapons in its security strategy so that it can afford the force that it needs in the future. A key part of that determination is whether the United States really needs a nuclear triad in 2075 that resembles the triad that existed in 1995 and, if it does, whether it is willing to sacrifice conventional military capability to buy that force.

Amy F. Woolf is a specialist in nuclear weapons policy at the Congressional Research Service (CRS). The views expressed in this article are those of the author and do not necessarily reflect those of the CRS or the Library of Congress.


1. David Alexander, “U.S. Needs Modern Nuclear Deterrent Despite High Price Tag--Hagel,” Reuters, January 9, 2014.

2. U.S. Department of Defense, “Nuclear Posture Review Report,” April 2010, pp. 21-22,

3. Office of the Press Secretary, The White House, “Fact Sheet: Nuclear Weapons Employment Strategy of the United States,” June 19, 2013.

4. The Obama administration has indicated that it would prefer to cooperate with Russia in negotiating this new limit. See U.S. Department of Defense, “Report on Nuclear Weapons Employment Strategy of the United States,” June 19, 2013,

5. National Defense Authorization Act for Fiscal Year 2014, Pub. L. No. 113-66, sec. 1055 (2013).

6. For a more detailed discussion of the modernization plans, along with alternatives that might reduce the costs, see Amy F. Woolf, “Modernizing the Triad on a Tight Budget,Arms Control Today, January/February 2012.

7. Congressional Budget Office (CBO), “An Analysis of the Navy’s Fiscal Year 2014 Shipbuilding Plan,” October 2013, p. 24,

8. CBO, “Projected Costs of U.S. Nuclear Forces, 2014 to 2023,” December 2013,

9. Presentation of Lieutenant General James M. Kowalski, May 7, 2013,

10. Jon B. Wolfsthal, Jeffrey Lewis, and Marc Quint, “The Trillion Dollar Triad,” James Martin Center for Nonproliferation Studies, January 2014,

11. See Joseph Cirincione, “Are New Nuclear Weapons Affordable?” The Huffington Post, December 20, 2013,; Tom Z. Collina, “Trimming the Bloated Nuclear Weapons Budget,” Arms Control Association, January 2014,; Michaela Dodge, “Americans Spend More on Pets Than on Nuclear Weapons,” Heritage Foundation, January 14, 2014,