Monroe Doctrine

In December 1823, President James Monroe used his annual message to Congress to declare that the United States would regard any further European colonization in the Americas, or European interference in the affairs of newly independent states there, as a threat to its own peace and safety. The statement, later named the Monroe Doctrine, had little immediate force behind it, but it became one of the most durable principles of American foreign policy and a foundation for the United States' claim to special influence in the Western Hemisphere.

The background lay in the upheavals of the early nineteenth century. Between roughly 1808 and the 1820s, Spain's American colonies broke away in a wave of independence movements, leaving Spain weakened and the future of the region uncertain. In Europe, the conservative powers of the Holy Alliance, including Russia, Austria, and Prussia, had supported restoring monarchies, and France had intervened in Spain in 1823 to restore its king. American leaders worried that these powers might help Spain reclaim its colonies. Russia's presence on the Pacific coast of North America, extending south from Alaska, added to the concern.

Britain also played a key role. Its merchants profited from trade with the new Latin American republics, and its government wanted to keep other European powers out. British foreign secretary George Canning proposed a joint Anglo-American statement opposing intervention. Monroe consulted former presidents Jefferson and Madison, who were inclined to accept. Secretary of State John Quincy Adams argued instead for a独立 American declaration, and historians generally credit him as the principal author of the doctrine's wording.

The message itself made several points. The Americas were no longer open to new colonization by European states. The United States would not interfere in existing European colonies or in Europe's internal wars. And any attempt by European powers to extend their political system to the hemisphere would be seen as hostile. At the time, the United States had a small navy and limited ability to enforce this. European governments largely ignored it, and Britain's naval power was the real barrier to intervention.

The doctrine's importance grew over time. It was invoked in the mid-nineteenth century during disputes over Texas, Oregon, and French involvement in Mexico. In 1904, Theodore Roosevelt added a "corollary" asserting a US right to intervene in Latin American countries to prevent instability, a move many in the region saw as justification for American domination. During the Cold War, the doctrine was cited in opposition to Soviet influence in Cuba. Latin American views of it have often been critical, though its meaning has shifted across two centuries.