Which strategy was employed by the United States in Vietnam that focused on gradual military involvement?

The correct answer relates to the policy of containment, which was a central aspect of U.S. foreign policy during the Cold War, particularly in relation to Vietnam. This strategy aimed to prevent the spread of communism, especially in Southeast Asia, where the U.S. believed a "domino effect" could occur if one country fell to communism.

In Vietnam, this gradual military involvement began in the late 1950s and accelerated through the early 1960s. Instead of an immediate full-scale invasion or military commitment, the U.S. started with advisory roles, financial support, and limited troop deployments to assist the South Vietnamese government in its conflict against the communist North. This incremental approach was intended to demonstrate U.S. commitment without triggering a larger confrontation, reflecting a careful application of military force based on the containment doctrine.

The other strategies mentioned, such as non-intervention, isolationism, and full-scale invasion, do not accurately describe the U.S. strategy in Vietnam during this period. Non-intervention and isolationism suggest a withdrawal or lack of engagement, which was not the case in Vietnam. Full-scale invasion implies an immediate and comprehensive military action, contrasting with the gradual escalation that characterized U.S. involvement during the early years of the