Forty years ago today the North Vietnamese and Vietcong launched the general offensive/general uprising, known to history as the Tet Offensive after the Vietnamese new year’s holiday during which it began. It was a last-ditch attempt at a quick win in a war the Communists knew they were losing. They thought that a series of attacks in South Vietnam’s urban centers would spark a civil uprising against the regime in Saigon, and the people would join them at the barricades. But within days it was clear the offensive had failed, and the general uprising was not forthcoming. By the end...