Monroe Doctrine

The Monroe Doctrine is a United States foreign policy position, first articulated by President James Monroe in his annual message to Congress on 2 December 1823, that opposes further European colonization or interference in the political affairs of the Western Hemisphere. Framed against the backdrop of newly independent Latin American republics and continuing European ambitions in the Americas, it held that the United States would regard any attempt by a European power to extend its political system to the hemisphere, or to interfere with the affairs of an independent American state, as a potentially hostile act, while pledging that the United States would not interfere in Europe's own internal affairs or existing colonies. Largely unenforceable by the still-young United States at the time it was issued, the doctrine grew in practical importance over the following century, and successive administrations invoked and expanded it, including through Theodore Roosevelt's early twentieth-century corollary asserting a U.S. right to intervene in the hemisphere. It became a central and long-lasting pillar of American strategic thinking about the Western Hemisphere well into the twentieth century.