At a time of widespread fears that a terrorist group or rogue state could carry out a horrific attack using weapons of mass destruction, it is easy to forget that the United States and the international community have worked quite successfully since the devastating U.S. bombings of Hiroshima and Nagasaki to establish standards against and prevent theuse and spread of nuclear, chemical, and biological weapons. The exceptions chill us: the near catastrophe of the Cuban missile crisis and the deadly use of chemical weapons in the bloody Iraq-Iran war. Yet, dire predictions that some 20 countries or more would be armed with nuclear weapons have not come true. And most countries have forsworn chemical and biological arms as legitimate weapons of war. These are not minor accomplishments. When arms control is mentioned, most people think of the Cold War"and for good reason. The latter years of that era were dominated by superpower negotiations and summits at which grimfaced U.S. and Soviet diplomats and leaders tried to limit each other"s burgeoning nuclear arsenals. What brought them together was the ever more costly, risky, and politically unpopular nuclear arms race; the stark reality of which became undeniable during the harrowing 13 days of the October 1962 Cuban missile crisis. Shortly thereafter, the two superpowers negotiated the Limited Test Ban Treaty. The treaty did not slow the nuclear arms race, but it did offer tangible health and environmental benefits by outlawing harmful nuclear testing in the atmosphere, at sea, and in outer space. It also showed the two rivals that regulating their competition did not have to be a zero-sum game and that it could, in fact, produce mutual gains. After determining that the introduction of missile defenses would only spur a buildup in offensive forces to overwhelm them, the two sides agreed to ban nationwide missile defenses in the 1972 Anti-Ballistic Missile Treaty. Treaties limiting offensive nuclear forces"SALT I, SALT II, the Intermediate- Range Nuclear Forces Treaty, and START I"soon followed. While these Cold War agreements did not end the U.S.-Soviet nuclear showdown, they helped manage it (and its aftermath), enabling the two sides and the world to avoid nuclear catastrophe Elisa D. Harris is a Senior Research Scholar at the Center for International Security Studies at Maryland.