Monroe Doctrine

CORE DEFINITION

The Monroe Doctrine is a U.S. foreign policy and ideology concerning control of the Americas, originating from President James Monroe in the early 19th century. Its main point is that the U.S. government believed European powers should not further colonize the Americas or interfere in the sovereign affairs of the United States, Mexico, and other American countries. The U.S. would remain largely neutral in disputes between European nations or between a European nation and its American colonies, but any such conflict occurring in the Americas would be viewed as hostile to the U.S. This was a turning point in U.S. foreign affairs, which remained until the outbreak of world wars. Until the late 19th century, Monroe's declaration was seen as the starting point defining fundamental U.S. foreign policy and one of the longest-lasting ideologies. Many U.S. politicians have invoked it, including presidents Ulysses Grant, Theodore Roosevelt, John F. Kennedy, Ronald Reagan, and Donald Trump. The purpose and influence of the Monroe Doctrine have lasted over a century with only minor changes.