Containment did not directly influence the United States' role in the Vietnam War. The United States' involvement in the Vietnam War was primarily driven by the policy of containment, which aimed to prevent the spread of communism. However, containment did not force the United States to support the Viet Cong or adopt a position of neutrality. Instead, the United States implemented a policy called Vietnamization, which aimed to transfer the responsibility of fighting the war to the South Vietnamese government and gradually withdraw U.S. troops. The policy of containment, combined with the belief in the domino theory, convinced the U.S. government that involvement in the Vietnam War was necessary to protect its strategic interests in Southeast Asia and stop the spread of communism.
