The specter of a nuclear holocaust lingers as the world approaches the 21st century. True, the end of the Cold War halted the U.S.-Soviet nuclear-arms race and prompted efforts to reduce strategic nuclear weapons. But the theory of nuclear deterrence -- which created a "balance of terror" during the Cold War -- dies hard, holding back progress toward nuclear disarmament.

In fact, nuclear powers are trying to devise new nuclear strategies in the uncertain post-Cold War world. No less disturbing is the emergence of nuclear-capable states with the potential to make the bomb. This clouds the prospects for nuclear nonproliferation and pushes the goal of total nuclear disarmament into the distant future.

The nuclear age dawned with the atomic bombings of Hiroshima and Nagasaki in 1945. The United States and the Soviet Union, locked in a deepening ideological contest, began all-out efforts to develop nuclear-weapons systems and established the enormous threat of nuclear war as the bedrock of their national security. The seemingly endless arms race, however, came to a grinding halt in the last years of the Soviet Union.