Scott D. Sagan notes that the question of why states seek to build nuclear weapons has scarcely been examined, although it is crucial to efforts at preventing proliferation. He challenges the traditional realist assumption, accepted uncritically by many scholars and policymakers, that states seek to acquire or develop nuclear weapons primarily for military and strategic reasons. Sagan examines alternate explanations for the demand for nuclear weapons.

Revised and updated versions of this article also appear as "The Causes of Nuclear Proliferation," Current History (April 1997), pp. 151-156; as "Why Do States Build Nuclear Weapons?" in Victor Utgoff, ed., The Coming Crisis: Nuclear Proliferation, U.S. Interests, and World Order (MIT Press, 1999), p. 17-50; and as "Why Do States Build Nuclear Weapons? Three Models in Search of a Bomb," in New Global Dangers: Changing Dimensions of International Security (International Security Reader, July 2004).

This article analyses whether the Nuclear Non-Proliferation Treaty (NPT) provides legal authority for International Atomic Energy Agency (IAEA) efforts to gain more information and more intrusive inspections to assure that non-nuclear-weapons States (NNWS) have joined the NPT are not attempting to make nuclear weapons in violation of that Treaty.

It is no exaggeration to say that arms control has undergone a revolution in the past decade. In the forty years since the bombings of Hiroshima and Nagasaki ended World War II and began the nuclear age, governments, organizations, and individuals have worked to reduce the threat of wars between great powers employing weapons of mass destruction-nuclear, chemical, and biological. Some progress was made during this period; the Limited Test Ban Treaty (LTBT) of 1963, the nuclear Non-Proliferation Treaty (NPT) of 1970, and the Anti-Ballistic Missile (ABM) Treaty and Biological Weapons Convention (BWC) of 1972 were the more notable achievements. But progress was always slow, frustrating, and tentative, with no assurance that the whole fabric might not be undone by an increase in superpower tension or by domestic forces in either the United States or USSR hostile to the very concept of arms control.

Based on interviews with participants and research in newly opened archives, the book reveals how the American atomic monopoly affected Stalin's foreign policy, the role of espionage in the evolution of the Soviet bomb, and the relationship between Soviet nuclear scientists and the country's political leaders.