Final answer:
The Eisenhower Doctrine was used to justify a military response during the crisis in Lebanon in 1958, where U.S. troops were deployed to counter a communist threat to the government.
Step-by-step explanation:
The Eisenhower Doctrine was a foreign policy position pronounced by President Dwight D. Eisenhower in response to the threat of communism spreading in the Middle East, particularly following the Suez Crisis. The doctrine asserted that the United States would provide economic and military assistance to countries in the region resisting control by international communism. The implementation of the Eisenhower Doctrine was evidenced in 1958 when Eisenhower authorized the deployment of U.S. troops to Lebanon to protect its government from communist-influenced political opponents, thereby using military response to counter the perceived communist threat.
The intervention in Lebanon under President Eisenhower's command was a direct application of the Eisenhower Doctrine, serving to protect a Middle Eastern nation from the influence and control of international communism. This was in accordance with the USA's Cold War strategy to contain and roll back communism.