Final answer:
The Vietnam War and changing domestic perceptions of the communist threat caused the U.S. to rethink its policies on containing communism. Difficulties in Vietnam and skepticism about the actual danger posed by communism led to questions about the effectiveness of such policies.
Step-by-step explanation:
The two domestic problems that led the United States to review its foreign policy of containing communism were the Vietnam War and the skepticism about the threat posed by communism. The Vietnam War, with its guerilla warfare and significant American casualties, brought about a national questioning of the containment policy and the effectiveness of military engagement in such conflicts. The American support for South Vietnam as part of its containment strategy proved problematic as this military approach did not easily adapt to the combat environment in Vietnam.
Additionally, the perceived threat of communism changed domestically during the early years of the Cold War. Increasingly, Americans doubted the extent of the threat that the Soviet Union and international communism represented, mirroring a similar skepticism that existed among some in the Soviet Union. The political climate of the time, however, pressured leaders in both the United States and the Soviet Union to make decisions within the context of the Cold War, leading to a reluctance to appear weak on communism and to discount opposing perspectives.
Overall, both the quagmire in Vietnam and the evolving perception of the communist threat at home led to a reevaluation of America's efforts to contain communism abroad, influencing both foreign and domestic policies during the period.