Despite the end of the Cold War, the issue of strategic missile defences will not go away in the 1990s. The Soviet Union will continue to retain thousands of nuclear missiles. Political turmoil may increase the chance of missiles being launched by rogue military leaders without proper political authorization. And Third World leaders are increasingly acquiring nuclear and chemical means of mass destruction as well as the ballistic missiles to carry them over long distances. Some have argued that these developments render the deployment of strategic defences more important than ever. This book evaluates this claim. It develops strategic, technical, and economic criteria for judging the value of deploying strategic defences. A detailed analysis of three specific strategic defence deployment options reveals that the deployment of strategic defences in the 1990s is unlikely to be strategically desirable, technically feasible, or economically affordable.