India’s decision in May 1998 to explode five nuclear devices of varying yields, including a thermonuclear device, has posed the most serious challenge to the existing nuclear non-proliferation regime since the coming into force of the Nuclear Non-Proliferation Treaty in 1970. It led to a Pakistani nuclear response, thus setting off fears of a nuclear arms race in South Asia. Furthermore, it provided Islamabad with a fresh opportunity to put Kashmir on the international agenda by ruing the escalating tensions on the subcontinent even as it exacerbated those tensions by intensifying the shelling across the Line of Control in Jammu and Kashmir. Finally, the Indian decision led to a marked deterioration in Indo-American relations and mutually hostile rhetoric not heard since the American “tilt” toward Pakistan during the 1971 Bangladesh crisis. U.S. imposition of economic sanctions on India, triggered automatically by congressional legislation, and Washington’s role in leading other G-8 countries to impose similar sanctions further damaged Indo-U.S. relations, even as Indochinese tension increased because of India’s invocation of the Chinese threat as a major, if not the prime, reason for its decision to go overtly nuclear.