Issues for Congress
This report focuses on the numbers and types of weapons in the U.S. strategic nuclear force structure. It does not address the broader question of why the United States chooses to deploy these numbers and types of weapons, or more generally, the role that U.S. nuclear weapons play in U.S. national security strategy. This question is addressed in other CRS reports. However, as the Obama Administration reviews and possibly revises the plans for U.S. nuclear force structure, Congress could address broader questions about the relationship between these forces and the role of nuclear weapons.
Force Size
The Bush Administration argued that, because the United States and Russia are no longer enemies, the United States would not size or structure its nuclear forces simply to deter the “Russian threat.” Instead, nuclear weapons would play a broader role in U.S. national security strategy. The Obama Administration, in contrast, noted that there is a relationship between the size of the U.S. arsenal and the size of the Russian arsenal. The 2010 NPR states that Russia’s nuclear force will remain a significant factor in determining how much and how fast we are prepared to reduce U.S. forces. Because of our improved relations, the need for strict numerical parity between the two countries is no longer as compelling as it was during the Cold War. But large disparities in nuclear capabilities could raise concerns on both sides and among U.S. allies and partners, and may not be conducive to maintaining a stable, long-term strategic relationship, especially as nuclear forces are significantly reduced. maintain a stable, long-term strategic relationship.” The Department of Defense is currently conducting a new study, as a follow-up to the NPR, to determine how deeply the United States might reduce its forces, and how it should deploy the remaining forces.
Press reports indicate the Pentagon is reviewing a number of alternatives in this study, including one that would reduce U.S. nuclear weapons to between 1,000 and 1,100 warheads, one that would reduce it to between 700 and 800 warheads, and one that would reduce it to between 300 and 400 warheads. According to Secretary of Defense Panetta, the planned New START force structure, with 1,550 warheads, is also an option for the future. In addition, according to the press reports, the United States would pursue these reductions through an arms control agreement with Russia, they would not come through unilateral cuts in the U.S. arsenal. When the study is complete, the Pentagon will present the alternatives to the President for his decision.
Some analysts have questioned why the United States must maintain such a large force of nuclear weapons. They have questioned whether the United States would attack with such a large number of weapons if its own national survival were not at risk, and they note that only Russia currently has the capability to threaten U.S. national survival. They assert that the United States could likely meet any other potential contingency with a far smaller force of nuclear weapons. Some have concluded, instead, that the United States also could maintain its security with a force of between 500 and 1,000 warheads. Others, however, dispute this view and note that the United States has other potential adversaries, and, even if these nations do not possess thousands of nuclear warheads, some may expand their nuclear forces or chemical and biological capabilities in the future. Some have argued that the also needs to assure its allies of its commitment to their security, and this goal could require a force of significant size, regardless of the number of potential targets an adversary nation might possess.
Force Structure
When the Bush Administration announced the results of the 200 I Nuclear Posture Review, it indicated that the United States would retain a triad of ICBMs, SLBMs, and heavy bombers for the foreseeable future. The Obama Administration also offered continuing support for the retention of the strategic triad. Nevertheless, as the Obama Administration has outlined plans to modernize and replace the delivery vehicles in all three legs of the strategic triad, many analysts have begun to question whether the United States can afford to retain the triad and whether it can retain a robust deterrent without one of the current types of strategic delivery vehicles.
The Obama Administration indicated, in the 2010 NPR, that the United States would convert some of its bombers to conventional-only missions. This is consistent with the view, among some analysts, that, in the future, the bombers may be more important in the conventional mission. As was noted above, most discussions about the bomber force focus on how many bombers, and what types of bomber weapons, the United States needs to bolster its conventional long-range strike capability. There is little, if any, discussion about the role that bombers may play in either nuclear deterrence, or, if deterrence fails, in the launch of U.S. nuclear weapons. It is not surprising that some in the Air Force and Pentagon, and some outside government have questioned the continuing need for nuclear-capable bombers.
The Obama Administration has indicated that the United States will retain up to 420 ICBMs under the New START Treaty. Each will be equipped with a single warhead. Analysts have often argued, and the 2010 NPR affirmed, that single-warhead ICBMs bolster crisis stability, and discourage efforts by an adversary to launch a disarming first strike, because the cost of the strike, as measured by the number of attacking warheads, would exceed the benefits, as measured by the number of warheads destroyed. But this calculus is not dependent on the number of ICBMs in the fleet. Moreover, these missiles will remain deployed at three ICBM bases.
The Obama Administration has indicated that it plans to retain 14 Trident submarines, at least through 2015, and then may reduce to 12 submarines. Moreover, the New START Treaty allows the United States to continue to reduce the warheads on each missile. It also allows the United States to eliminate some of the launch tubes by simply removing the gas generators that assist in the launch of the missiles. As a result, the United States will have a significant amount of flexibility in apportioning warheads among its SSBNs, and will almost certainly not have to eliminate any submarines to meet the new START limits. As a result, with its ability to remain invulnerable to detection and attack, and with the increasing accuracy and reliability of its missiles and warheads, the Trident fleet will continue to represent the backbone of the U.S. nuclear force.
The United States does not plan to alter the basic structure of its Trident fleet; it will continue to deploy its submarines at two bases, with a portion of the fleet deployed in the Atlantic Ocean and a portion deployed in the Pacific Ocean. However, if the United States reduces the size of its nuclear arsenal significantly below the limits in the New START Treaty, the United States may find it difficult to retain its triad of nuclear delivery vehicles. Presidents Obama and Medvedev have pledged to reduce nuclear weapons in a step-by-step process, with additional reductions coming in a future treaty. Most analysts who propose deep reductions, to perhaps 1,000 nuclear warheads, readily acknowledge that these reductions could affect the U.S. triad, and support changes in the U.S. force structure.
Some argue that the United States should retain only the warheads on its Trident submarines. It could convert its bombers to conventional missions and perhaps eliminate its land-based ICBMs. However, the United States might also have to reduce the size of its Trident fleet, from the current 14 submarines to perhaps 8 or 10 submarines, if it reduced to 1,000 warheads. And, with so few submarines, the United States might have to eliminate one of its submarine bases, leaving it with submarines based only in the Atlantic or only in the Pacific Ocean. This change may not be consistent with current submarine operations and employment plans. President Obama and the U.S. military may want to consider the implications of these basing, operational, and policy changes, before deciding whether or not to reduce to 1,000 warheads, as opposed to choosing the warhead number first then deciding later how to base and operate the remaining nuclear forces.
