Radio Warfare examines the propaganda strategy of Hitler's Germany, British responses to this strategy, and the effect of British actions on U.S. psychwar techniques. The book's emphasis is U.S. subversive warfare during World War II, for studies of British and German psychological warfare strategy during this conflict have been described elsewhere. Serfton Delmer's Black Boomerang (1962), Charles Cruickshank's The Fourth Arm (1977), and Ellic Howe's The Black Game (1982) are studies of British subversive warfare techniques. J. A. Cole's Lord Haw-Haw and William Joyce (1965) and Willi Boelke's Die Macht des Radio (1977) examine German subversive propaganda. Radio Warfare is the first study of the United States' radio warfare methods.