Working Group: ICBMs Still Vital To Deterrence

Last Friday the Lexington Institute sponsored a working group on the future of the Intercontinental Ballistic Missile force. The meeting attracted diverse participation from government, industry and academia, with conversation centering on how the ICBM force is likely to fare in the Obama Administration’s nuclear posture review and arms control negotiations. The 1991 Strategic Arms Reduction Treaty (START) will expire in December, and the posture review is being used to determine what kind of force the U.S. can accept under a successor agreement.

The United States currently sustains 450 single-warhead Minuteman III missiles in hardened silos at 15 launch complexes. The ICBMs are one component of a nuclear “triad” that also includes 14 Trident ballistic-missile submarines and several dozen long-range bombers. Under the current treaty, the U.S. is allowed to maintain 1,600 nuclear delivery vehicles (missiles and bombers), but the administration probably will agree to cut that number to between 500 and 1,100. It also probably will agree to cut the number of deployed nuclear warheads from a maximum of 2,200 to fewer than 1,700.

Cuts of this magnitude could easily result in the elimination of one leg of the triad. However, most working-group members felt that retention of a triad was desirable even at lower numbers in order to preserve a secure retaliatory force. Under current U.S. nuclear strategy, the assured ability to retaliate after suffering a surprise attack is central to maintaining deterrence. Several participants noted that having a diverse triad of distinctly different weapons made a disarming attack less feasible, and thus strengthened nuclear stability. That same reasoning prevailed during the Cold War, and could arguably become more compelling if the number of weapons in the arsenal continues to shrink.

One participant argued that aging of the bomber fleet is so advanced the nation is on the verge of having a nuclear “dyad,” rather than a triad. With no new bomber in prospect — Secretary Gates proposed cancellation of a next-generation bomber in April — the credibility of nuclear deterrence might come to depend solely on ballistic missiles in silos and at sea. The 14 Trident subs would probably be the most survivable component of this “dyad,” but some are not at sea at any given time, and a breakthrough in undersea warfare could put much of the deterrent at risk. ICBMs thus remain crucial to deterrence. However, the industrial base for building ICBMs is declining rapidly, which creates some urgency about defining precisely what kind of force will be needed in the future.