Monroe Doctrine: The Monroe Doctrine was a US foreign policy stating that any European attempts to colonize or interfere in the Americas would be seen as a threat to US interests and potentially provoke military intervention.
Truman Doctrine: The Truman Doctrine was a US foreign policy that provided economic and military assistance to countries threatened by communism.
Bush Doctrine: The Bush Doctrine was a set of principles adopted by the United States during President George W. Bush's administration, emphasizing preemptive strikes against perceived threats to national security.