Abstract/Summary

The Treaty on the Non-Proliferation of Nuclear Weapons (NPT) faced a serious threat only a few years after it came into force in 1970. India’s “peaceful nuclear explosion” (PNE) in May 1974 rocked the nuclear-nonproliferation regime and cast doubt on the prospects of the NPT. Yet during the two years following the PNE, several significant countries ratified the treaty. Why did states that had been notable holdouts, like Italy, Japan, and South Korea, ratify the treaty soon after the Indian nuclear test? This article finds that the PNE galvanized pro-NPT forces in the United States and Canada, leading to changes in nonproliferation policy. In particular, it led them to threaten to withhold access to nuclear technology and materials unless the holdouts ratified the NPT. It also motivated Secretary of State Henry Kissinger to change his secret advice to Japan that the United States did not want Japan to ratify the NPT in order to keep the People’s Republic of China unsure about Japan’s nuclear intentions.