The impact of foreign policy shifts in post-war America can be observed in its commitment to containment of communism and the establishment of international alliances. The implementation of the Truman Doctrine in 1947, focusing on providing support to nations resisting communism, marked a key shift in U.S. foreign policy. With initiatives like the Marshall Plan, America sought to rebuild Europe and prevent the spread of Soviet influence. These policies led to the formation of alliances such as NATO, shaping the geopolitical landscape during the Cold War. The U.S. also took an active role in various conflicts worldwide, promoting democracy and capitalism.