Module 4: American Forces in Vietnam

American Forces in Vietnam

After the Gulf of Tonkin Incident in August 1964, President Lyndon B. Johnson (LBJ) sought and received broad authority from Congress through the Gulf of Tonkin Resolution, which allowed for the escalation of U.S. military involvement in Vietnam. Johnson, determined to prevent the fall of South Vietnam to communism and to uphold the credibility of U.S. commitments under the "domino theory," significantly increased American military presence. In the years that followed, the number of U.S. troops in Vietnam grew from about 16,000 in 1963 to more than 500,000 by 1968. Johnson's policy of "escalation" focused on using heavy air strikes and ground operations to defeat both North Vietnamese regular forces and the Viet Cong insurgents in South Vietnam. This strategy aimed to break the stalemate and force North Vietnam to negotiate, but it faced considerable challenges in the form of guerilla warfare tactics employed by the Viet Cong, who blended into the civilian population and relied on hit-and-run tactics to counter the superior firepower of American forces.

Meanwhile, the political situation in South Vietnam remained unstable. In 1963, South Vietnamese President Ngo Dinh Diem, a key U.S. ally, was overthrown and killed in a coup, further destabilizing the country. Diem's regime had become deeply unpopular due to his authoritarian rule, corruption, and persecution of Buddhist religious groups, which led to widespread protests. The U.S. had grown disillusioned with Diem, and while it had initially supported his government, it ultimately tacitly endorsed the coup that removed him from power. Following Diem's death, a series of weak and unstable governments took power in South Vietnam, further complicating the American effort to stabilize the region. The South Vietnamese Army (ARVN), which the U.S. had been training and equipping, was plagued by poor leadership, corruption, and a lack of cohesion, undermining efforts to defend the country from both North Vietnamese regulars and the Viet Cong.  In fact, many ARVN soldiers secretly supported North Vietnamese war aims.

As the war escalated, the U.S. faced increasing challenges, both on the battlefield and at home. The heavy use of the Selective Service System, which called up draftees to fight in Vietnam, led to growing protests and opposition to the war, especially among younger Americans. By 1968, the war had become deeply unpopular, with increasing casualties, mounting costs, and a lack of clear progress. The U.S. military had not been able to defeat the Viet Cong, who used guerilla tactics and enjoyed significant local support. Despite large-scale bombing campaigns and search-and-destroy missions, the North Vietnamese and Viet Cong were able to continue fighting. In early 1968, the Viet Cong and North Vietnamese forces launched the Tet Offensive, a massive, coordinated attack on major cities and military bases in South Vietnam, including the capital, Saigon. Though militarily unsuccessful for the North, the Tet Offensive was a psychological and political turning point, exposing the gap between optimistic reports from the Johnson administration and the reality of the war. The offensive severely damaged American public confidence in the war effort and marked a turning point in U.S. involvement, signaling that victory in Vietnam was far from certain.