“International safeguards” refer to a set of international agreements establishing control over the production, use, and final disposition of fissionable materials. Before the Non-Proliferation Treaty (NPT) went into effect, International Atomic Energy Agency (IAEA) safeguards had been applied to 75 reactors and ten other nuclear facilities under 51 different agreements. The design of the first regime was largely a function of political, strategic, and economic rather than technical considerations. After 1971, safeguards were made an integral part of the NPT, and became obligatory with respect to all peaceful nuclear activities in signatory states. Negotiations on the NPT safeguards regime focused on efforts to minimize the major asymmetrical costs that this implied, and particularly to meet the objections of major nonnuclear weapons states. The focus of controversy centered less on resistance to incursions on sovereignty than on demands for equity in incursion. In these negotiations, technological factors facilitated the construction of a politically acceptable regime.