This text provides a comprehensive narrative history of U.S. involvement in Southeast Asia, from 1942 to 1975—with a concluding section that traces U.S.-Vietnam relations from the end of the war in 1975 to the present. Unlike most general histories of U.S. involvement in Vietnam—which are either conventional diplomatic or military histories—this text synthesizes the perspectives to explore both dimensions of the struggle in greater depth, elucidating more of the complexities of the U.S.-Vietnam entanglement. It explains why Americans tried so hard for so long to stop the spread of Communism in Indochina, and why they ultimately failed.