U.S. Strategic Nuclear Forces: Background, Developments, and Issues [June 14, 2013] [open pdf - 476KB]
"During the first Obama Administration, Congress reviewed the 2010 Nuclear Posture Review, the 2012 New START [Strategic Arms Reduction Treaty] Treaty, and funding plans for the U.S. nuclear enterprise. Specifically, even though the United States plans to reduce the number of warheads deployed on its long-range missiles and bombers, consistent with the terms of the New START Treaty, it also plans to develop new delivery systems for deployment over the next 20-30 years. The 113th Congress will continue to review these programs during the annual authorization and appropriations process. During the Cold War, the U.S. nuclear arsenal contained many types of delivery vehicles for nuclear weapons. The longer-range systems, which included long-range missiles based on U.S. territory, long-range missiles based on submarines, and heavy bombers that could threaten Soviet targets from their bases in the United States, are known as strategic nuclear delivery vehicles. At the end of the Cold War, in 1991, the United States deployed more than 10,000 warheads on these delivery vehicles. That number has declined to less than 2,000 warheads today, and is slated to decline to 1,550 warheads by the 2018, after the New START Treaty completes implementation. At the present time, the U.S. land-based ballistic missile force (ICBMs) consists of 450 Minuteman III ICBMs [Inter-Continental Ballistic Missile], each deployed with between one and three warheads; they will all be reduced to only one warhead over the next few years, and the fleet will decline to, at most, 420 missiles. The Air Force is also modernizing the Minuteman missiles, replacing and upgrading their rocket motors, guidance systems, and other components. The Air Force had expected to begin replacing the Minuteman missiles around 2018, but decided, instead, to continue to modernize and maintain the existing missiles, so that they can remain in the force through 2030; it is, once again, considering what to do to sustain the missiles after 2030."
CRS Report for Congress, RL33640