The Monroe Doctrine, articulated by President James Monroe in 1823, significantly shaped U.S. foreign policy by asserting that European powers should no longer colonize or interfere in the Western Hemisphere. It was a declaration of U.S. interests in the Americas, suggesting that any foreign intervention would be viewed as a threat to the security of the United States. The doctrine asserted U.S. influence in Latin America, and while initially more symbolic than enforceable, it laid the groundwork for American intervention in the region's affairs throughout the 19th and 20th centuries. It established a precedent for U.S. dominance in the western hemisphere.