More than a quarter of a century after the last Marine Corps Huey left the American embassy in Saigon, the lessons and legacies of the most divisive war in twentieth-century American history are as hotly debated as ever. Why did successive administrations choose little-known Vietnam as the "test case" of American commitment in the fight against communism? Why were the "best and brightest" apparently blind to the illegitimacy of the state of South...