China, India, Pakistan, Russia, United States
Acton, James. "Bombs Away? Being Realistic about Deep Nuclear Reductions." The Washington Quarterly 36, no. 2 (Spring 2013): 37-53.
From the publisher: There are about 22,000 nuclear warheads in the world today. Reducing that number—eventually to zero—is a major element of U.S. President Barack Obama’s foreign policy. To date, his administration’s progress toward this goal has been modest, even with agreement on a new round of U.S.–Russian cuts with the New START treaty. Nonetheless, opponents of his agenda, particularly in Congress, worry that any further arms control will pitch the United States down a slippery slope toward zero. Simultaneously, supporters increasingly complain that Obama has not been bold enough. Their frustration, which is felt in capitals across the world, risks compromising the willingness of key states to support important U.S. foreign policy objectives, especially those related to nonproliferation.
Neither these fears nor these frustrations are fair. Skeptics and supporters tend to ignore the practical realities of deep reductions. Nuclear-armed states will only agree to deep reductions if at least three demanding conditions are met: arms build-ups in China, India, and Pakistan must be stabilized; nuclear-armed states—especially Russia and China—will have to be convinced that arms control will not undermine the survivability of their nuclear forces; and nuclear-armed states will have to be satisfied that reductions will not exacerbate existing imbalances in conventional forces.