Continued expansion of the nuclear weapons capabilities of India and Pakistan, coupled with ongoing conflict between them, raises the probability of nuclear war in South Asia. A nuclear arms race between India and Pakistan could also harm efforts to discourage other nations from acquiring nuclear weapons. United States policy opposes the spread of nuclear weapons because proliferation increases threats to U.S. national security and to world peace and stability. However, there is debate on the dangers of an escalating arms race in South Asia. Steps taken by the United States and other countries to persuade India and Pakistan to end their nuclear weapons programs have had limited success, at most slowing down their pace. A complicating factor is that India maintains a nuclear capability in part to deter China, whereas Pakistan's nuclear weapons capability is aimed at deterring India's superior conventional and nuclear capabilities. Analysts and policy officials are divided on how to avoid an arms race in South Asia. The Clinton Administration has renewed efforts to break the deadlock over nonproliferation, but longstanding obstacles have blocked progress. Pakistan favors a regional approach to nonproliferation, while India insists on a global approach that treats the nuclear powers on an equal basis with non nuclear weapon countries. This report analyzes the nuclear capabilities of India and Pakistan and reviews several options for U.S. nonproliferation policy in South Asia.