In recent years, the dangers associated with nuclear weapons and the complexities of addressing these dangers have steadily grown. Relations with a nucleararmed Russia could become adversarial. China’s level of strategic development of nuclear technology remains unclear. Nuclear technologies are illicitly transferred through black markets. Equally important, new threats continue to grow from emerging nuclear states, such as Iran and North Korea, and from terrorist groups who may gain access to nuclear weapons. In this new and dangerous world, the United States must address and reassess its nuclear weapons policy.