Most people think Star Wars was Reagan's idea, but its roots reach decades farther back. Military historian Don Baucom traces them to the dawn of the atomic age in 1944.

In this first scholarly account of the origins of SDI, Baucom brings together the political, technological, and strategic forces that have shaped the history of ballistic missile defenses from World War II to the present day. He chronicles major technological developments and shows how SDI emerged in 1983 from the technological and strategic legacies of the ICBM, ABM, SALT, and SAFEGUARD programs.

Surprisingly, Baucom...