The United States and Russia have engaged in negotiations to limit and reduce their respective nuclear arsenals for more than 40 years. The successful conclusion of the New Strategic Arms Reduction Treaty (New START) in 2010 marked the latest step in this process and, according to Pres. Barack Obama, set the stage for even more reductions.1 In a June 2013 speech, the president in fact reaffirmed his intention to seek further negotiated cuts with Russia.
The other declared nuclear weapon states—China, France, India, Pakistan, and the United Kingdom—have so far not played a direct role in this process. Since the United States and Russia possess the largest and most diverse arsenals, comprising nearly 90 percent of the world's nuclear weapons, the more-modest nuclear capabilities of these other nations have heretofore had only a minimal effect on the overall strategic balance and notions of stability between the two nuclear superpowers.
That, however, may be changing. If the United States and Russia do indeed significantly lower their numbers of nuclear weapons in the years ahead, the relative proportion of nuclear capability represented by the other five countries could significantly increase. Such a development would have two important implications. First, it would raise the question of how the theories of nuclear deterrence, originally developed in a bilateral and Cold War context, will apply in an international system with several nations holding nuclear weapons numbering "in the hundreds." It also suggests that the nuclear arsenals of the other nuclear weapon states will become an important factor in any future US-Russian discussions on nuclear reductions.