MAP 26.1 The Vietnam War, 1968 The United States wielded vastly more military personnel and weaponry than the Vietcong and North Vietnamese but faced a formidable challenge in fighting a guerrilla war in a foreign country. Massive American bombing failed to defeat the North Vietnamese or stop their troop movements and supply lines along the Ho Chi Minh Trail. The 1968 Tet Offensive demonstrated the shortcomings in the U.S. strategy.