This book looks at the historic use of foreign language by the U.S. armed forces. Through research into military documents, many of which are generally inaccessible, the author has investigated the purpose and extent of language capability in the armed services. A necessary skill in the acquisition of intelligence, language skill emerges from this study as being of concern as well for command, control, communications, and for civil military operations. The services' efforts to produce language skills are presented historically, from World War I through Vietnam, from extensive cooperation with academic institutions to short-term services contracted from entrepreneurs.