U.S. Strategic Nuclear Concepts in the 1970s: The Search for Sufficiently Equivalent Countervailing Parity

The United States confronted three important decisions in the late 1960s affecting the state of the Soviet-American strategic nuclear balance: whether to deploy antiballistic missile systems (ABMs), which had the potential of greatly reducing the destruction that a nuclear attack might produce, especially in a second strike (unless the opponent had offset the defensive effect of the ABMs by adding to its own offensive warheads); whether to deploy multiple independently targetable reentry vehicles (MIRVs), which had the potential of enabling whichever side struck first to deprive the other of its fixed-site intercontinental ballistic missiles (ICBMs) as secure second-strike weapons (unless the opponent had offset the offensive effects of the MIRVs by multiplying its fixed sites or defending them); and whether to deploy additional forces to keep pace with the additions the Soviet Union was making to its offensive forces, additions which (unless offset) had the potential of changing the strategic balance from one of American superiority to one of parity or even, perhaps, Soviet superiority. By the mid-1970s, the United States had made all three decisions. It decided to avoid, if it could, the deployment of ABMs, and in 1972 the United States and the Soviet Union signed a treaty limiting ABMs to nominal levels and banning the deployment of other forms of ballistic missile defense. In contrast to their approach to ABMs, neither the United States nor the Soviet Union made a determined effort to negotiate an agreement to ban MIRVs or to limit them to nominal levels. The United States began to deploy MIRVed ICBMs in 1970 and MIRVed submarine-launched ballistic missiles (SLBMs)