Which of the following warned European powers not to interfere in the affairs of the Western Hemisphere?

The Truman Doctrine, articulated in 1947, aimed to contain the spread of communism by providing political, military, and economic assistance to countries threatened by Soviet influence. While significant in the context of the Cold War, it does not address European interference in the Western Hemisphere, focusing instead on global communist threats.

The Wade-Davis Bill, proposed in 1864 during the American Civil War, sought to set strict requirements for the re-admittance of Southern states into the Union. This legislation was not related to foreign policy or European intervention in the Western Hemisphere, making it irrelevant to the question.

The Tonkin Gulf Resolution, passed in 1964, authorized military action in Vietnam following reported attacks on U.S. naval vessels. While it marked a significant escalation in U.S. involvement in Vietnam, it does not pertain to the issue of European powers interfering in the Western Hemisphere.