Defense against nuclear attackso natural and seemingly so compelling a goalhas provoked debate for at least twenty years. Ballistic missle defense systems, formerly called antiballistic missile systems, offer the prospect of remedying both superpowers'' alarming vulnerability to nuclear weapons by technological rather than political means. But whether ballistic missile defenses can be made to work and whether it is wise to build them remain controversial. The U.S.-Soviet Anti-Ballistic Missile Treaty of 1972 restricts testing and deployment of ballistic missile defenses but has not prohibited more than a decade of research and development on both sides. As exotic new proposals are put forward for space-based directed-energy systems, questions about the effectiveness and wisdom of missile defense have again become central to the national debate on defense policy.
This study, jointly sponsored by the Brookings Institution and the Massachusetts Institute of Technology, exami
