The Monroe Doctrine was a U.S. foreign policy declared by President James Monroe on December 2, 1823, aimed at opposing European colonialism and political intervention in the Americas. It asserted that the Western Hemisphere was no longer open to colonization by European powers and that any attempt by European countries to interfere with independent nations in the Americas would be considered a hostile act against the United States. The doctrine also stated that the U.S. would not interfere in European affairs or with existing European colonies in the Americas
. The doctrine had four main points:
- The U.S. would not interfere in European internal affairs or wars.
- The U.S. recognized and would not interfere with existing European colonies in the Americas.
- The Western Hemisphere was closed to future colonization.
- Any European attempt to oppress or control nations in the Americas would be seen as hostile to the U.S.
Originally, the Monroe Doctrine was a defensive policy to protect the newly independent Latin American countries from European recolonization and to safeguard U.S. interests and expansion in the hemisphere. Although initially ignored by European powers due to the U.S.'s limited military strength, it was later enforced more effectively, especially by the British navy and eventually by the U.S. itself in the 20th century
. The doctrine was invoked several times, such as during the U.S. support for Mexico against French intervention in the 1860s. Over time, it evolved, with additions like the Roosevelt Corollary allowing U.S. intervention in Latin America under certain conditions, and later policies like the Good Neighbor Policy emphasizing non-intervention
. In summary, the Monroe Doctrine established the U.S. position as protector of the Western Hemisphere against European interference and became a cornerstone of American foreign policy for over a century
