the prospects for near-term action on the two sides in this direction. Some dilemmas of nuclear deterrence that were instrumental in shaping nuclear arsenals during the Cold War, along with the dangers that resulted, are then briefly elaborated. The committee outlines its case for a regime of progressive constraints to continue the progress that has been made in reducing those dangers since the Cold War ended. The chapter concludes with an orientation to the remainder of the report and a caution about the economics of nuclear arms reductions.
During the Cold War, nuclear weapons were at the center of U.S. and Soviet national security strategies. Both countries developed large, diverse, dispersed, and accurate nuclear forces that were maintained at high alert levels. (Appendix B portrays the Cold War growth of nuclear forces, as well as the beginnings of their post-Cold War decline.) The officially stated rationales for these forces, in broad terms, were on the U.S. side to deter the Soviet Union from attacking or threatening to attack the United States or its allies with either conventional forces or nuclear weapons (see Box 1.1) and on the Soviet side to deny the United States and its allies any military or political advantage from their possession of nuclear weapons, and to be able to deliver a "crushing rebuff" to any use of nuclear weapons against the Soviet Union.
The actual events of the Cold War period are consistent with the view that the nuclear forces and policies of the two sides were successful in their stated purposes: from 1946 onward, neither side succeeded in consistently imposing its will on the other, neither waged major war against the other, and neither launched a nuclear attack against anyone. Of course, other factors were at work, including the memory of the vast destruction of World War II, nearly all of it accomplished with conventional forces. And proof of cause and effect is always elusive in international affairs, as is, even more generally, proof of why something did not happen.
But supposing that the nuclear forces and policies of the two sides were indeed major contributors to the avoidance of full-scale war between East and West in the post-1945 period, it still must be conceded that this outcome was accompanied by enormous risks. These risks included the danger that the nuclear arms competition might continue without limit, endlessly adding to destructive potentials, constantly risking some destabilizing imbalance, and forever tempting additional countries to acquire nuclear weaponry for purposes of protection, or status, in a world of nuclear-armed camps. Above all, the risks included the danger that an accidental, erroneous, or unauthorized launch of one or a few nuclear weapons, or some other escalatory dynamic arising out of political crisis or regional conflict, could lead to full-scale nuclear war and the unimaginable disaster that this would represent for civilization (see Box 1.2).5