Cancel Development and Production of the New Missile in the Ground-Based Strategic Deterrent Program

Background

The United States' long-range nuclear forces consist of intercontinental ballistic missiles (ICBMs) carrying nuclear warheads, ballistic missile submarines carrying submarine-launched ballistic missiles (SLBMs), and long-range bombers carrying nuclear bombs and cruise missiles. That configuration is often referred to as the strategic nuclear triad. Each segment of the triad contributes to nuclear deterrence in different ways that complement the others. ICBMs provide the ability to respond promptly to an attack. Furthermore, because the silos that house ICBMs are hardened against nuclear attack and are well separated from other silos, each missile would have to be destroyed individually, which sets a high threshold for an adversary to deliver a debilitating attack on U.S. nuclear forces. Ballistic missile submarines operating at sea are very hard to detect and thus would be likely to survive any attack on U.S. nuclear forces and ensure that the United States could retaliate. Bombers provide flexibility and the ability to signal intent during a crisis (by increasing their pace of operations or being visibly deployed to crisis regions).

The United States currently fields 400 ICBMs distributed among 450 active silos at three bases. That force includes Minuteman III missiles, the last of which entered service in the 1970s and which have been refurbished several times. The Air Force plans to replace those missiles with new missiles when the current inventory reaches the end of its useful life, around 2030. As part of the Ground-Based Strategic Deterrent (GBSD) program, the Department of Defense (DoD) will design a new ICBM, build about 640 of those missiles, and refurbish the existing silos, ICBM support equipment, and command-and-control systems. Minuteman III missiles currently carry W78 and W87 warheads, which are sustained by the Department of Energy (DOE). Over the coming years, DOE plans to design and build interoperable warheads (IWs), which would replace the existing warheads for SLBMs and ICBMs.

Option

Under this option, the new missile portion of the GBSD program would be canceled, and the IW program would be replaced with less complex life-extension programs (LEPs) on the SLBM warheads (the W76 and the W88). The current Minuteman III missiles, along with their W78 and W87 warheads, would continue to operate until they reached the end of their operational lifetime. Refurbishment of the silos, command-and-control systems, and other support equipment would continue as planned under the GBSD program.

Effects on the Budget

This option would reduce budget authority by about $30 billion over the next 10 years relative to the costs of DoD's 2019 plan, the Congressional Budget Office estimates. Outlays would decrease by about $24 billion over that period. Savings in outlays would be delayed relative to budget authority because developing new systems requires extensive research and planning and because DoD distributes funding as expenses are incurred. Most of the savings would come from forgoing development and initial production of the new ICBM as part of the GBSD program. Additional savings would result from cancellation of the IW programs, although some of those savings would be offset by the costs of replacing the IWs with LEPs on the current SLBM warheads.

Most of the savings from this option would occur after the 10-year period. DoD plans to produce the new ICBM and its interoperable warheads into the 2030s. In addition, operation and support costs for ICBM forces and warheads would end after the Minuteman III missiles were retired.

CBO's estimate of the costs to develop the new ICBM is based on the actual costs to develop the Minuteman III, inflated to current dollars and then increased by 50 percent to account for cost growth between generations of missiles. CBO estimated the cost of the first production unit of the ICBM by applying a parametric model based on engine thrust and other technical parameters (assuming the new missile would have parameters similar to those of the Minuteman III). CBO's estimate of the costs of the IW programs is based on DOE's plans. All of those estimates are very uncertain. Programs that have developed new weapon systems historically have experienced cost growth relative to early estimates, and both the missile and warhead programs are in the early planning stages.

CBO's estimate of savings is based on full cancellation of the new ICBM and its warheads, forgoing both development and subsequent production. If DoD and DOE chose instead to continue those programs but to reduce the quantity purchased, savings would be substantially smaller. That is because the development efforts, which constitute most of the 10-year savings, would persist.

Other Effects

One argument for this option is that the likelihood of a large-scale disabling nuclear strike—the threat most subject to deterrence by ICBMs—is much lower now than during the Cold War, according to some analysts. If a large-scale strike did occur, the United States would still have several hundred warheads available for a retaliatory strike as long as U.S. nuclear submarines at sea remain undetectable, so deterrence would still be effective. Furthermore, some analysts argue that ICBMs provide little value in the modern multipolar nuclear environment in which regional conflicts could escalate to war and limited nuclear strikes present the most pressing risks. Advocates of this option would also argue that ballistic missile submarines are capable of carrying more nuclear warheads than they do currently, so the reduction of 400 warheads coming from no longer fielding ICBMs in the 2030s could be offset by increasing the number of warheads carried on SLBMs. Thus, this option would not necessarily represent a reduction in the number of warheads fielded by the United States.

One argument against this option is that it would decrease strategic stability. Some analysts argue that reducing the ICBM force would increase the risk of an attack because the number of sites an adversary would have to destroy in a disabling strike on U.S. land-based nuclear forces would decline from almost 500 to around 20. Another argument against this option is that it could lead to nuclear proliferation if the retirement of the ICBM force in the 2030s was viewed by allies as being significant enough that they questioned U.S. security assurances (backed by U.S. nuclear weapons) and decided to pursue their own nuclear arsenals.