Vietcong soldiers climb onto a U.S. tank abandoned on a road in Hue during the Tet Offensive in 1968. The series of shocking, highly coordinated Vietcong attacks throughout South Vietnam was, in fact, a strategic failure for communist forces, who'd hoped to spark a general uprising. But, more importantly, it helped to turn a large and vocal portion of an already fatigued American public -- battered by domestic and international crises -- against U.S. involvement in Vietnam. That year, 1968, would become the deadliest of the war for American troops, with more than 16,000 killed. While a defeat, in terms of casualties and territory lost, for North Vietnam, the Tet Offensive was also the beginning of the end of American military dominance in Southest Asia.