Which Asian country experienced a military loss for the US during attempts to contain communism?

The United States experienced a significant military loss in Vietnam during its efforts to contain communism. The Vietnam War, which lasted from the late 1950s until 1975, was a pivotal conflict in the Cold War era where the US intervened to support the government of South Vietnam against the communist forces of North Vietnam. Despite substantial investments in terms of military personnel and resources, the conflict ultimately resulted in a withdrawal of US forces and the fall of Saigon in 1975, leading to the unification of Vietnam under communist control. This outcome is often seen as a critical defeat for the US, illustrating the complexities and challenges associated with containing communism in Southeast Asia.

In contrast, while Korea saw significant military action, resulting in a stalemate and the ongoing division between North and South Korea, it is not categorized as a direct loss for the US. China, having undergone a communist revolution earlier in 1949, was not a country where the US fought directly to contain communism in the same military context. Laos also experienced conflict during this time, but it was less significant in terms of direct military engagement by the US like in Vietnam.