Monroe Doctrine, statement of United States policy on the activities and rights
of European powers in the western hemisphere. It was made by President James
Monroe in his seventh annual address to the U.S. Congress on December 2,
1823; it eventually became one of the foundations of U.S. policy in Latin America.
Because it was not supported by congressional legislation or affirmed in
international law, Monroe's statement initially remained only a declaration of
policy; its increasing use and popularity elevated it to a principle, specifically
termed the Monroe Doctrine for the first time after the mid-1840s.
The Original Statement
In his two most notable pronouncements, Monroe asserted that European
powers could no longer colonize the American continents and that they should
not interfere with the newly independent Spanish American republics. He
specifically warned Europeans against attempting to impose monarchy on
independent American nations but added that the U.S. would not interfere in
existing European colonies or in Europe itself. The last point reaffirmed George
Washington's Farewell Address in 1796, in which he urged the U.S. to avoid
By thus separating Europe from America, Monroe emphasized the
existence of distinct American and specifically U.S. interests. He rejected the
European political system of monarchy, believing that no American nation would
adopt it and that its presence anywhere in the western hemisphere endangered
the peace and safety of the young U.S. He also implied that the U.S. alone
should complete the remaining settlement of North America.
Despite the boldness of his assertions, Monroe provided no means to ensure the
enforcement of his ideas, although he knew that Great Britain, with its powerful
navy, also opposed European intervention in Spain's struggle to restore its
Further Development in the 19th Century
As far as the U.S. was concerned, the Monroe Doctrine meant little until
the 1840s, when President James Polk used it to justify U.S. expansion. In 1845
he invoked the doctrine against British threats in California and Oregon, as well
as against French and British efforts to prevent the U.S. annexation of Texas. In
1848 Polk warned that European involvement in the Yucatán could cause the
U.S. to take control of the region. Despite Polk's use of the doctrine and its
increasing popularity in the 1850s, the American Civil War greatly reduced its
effectiveness during the 1860s; hence, Spain's reacquisition of the Dominican
Republic (1861) and France's intervention in Mexico (1862-67) went largely
During the 1870s and '80s the doctrine took on new meaning. The U.S.
began to interpret it both as prohibiting the transfer of American territory from one
European power to another and as granting the U.S. exclusive control over any
canal connecting the Atlantic and Pacific oceans through Central America. The
latter claim was recognized by Great Britain in the Hay-Pauncefote Treaty
(1901). The U.S. continued to expand the meaning of the doctrine when
President Grover Cleveland successfully pressured Great Britain in 1895 to
submit its boundary dispute with Venezuela to arbitration.
The Monroe Doctrine in the 20th Century
In 1904 President Theodore Roosevelt claimed that the U.S. could
intervene in any Latin American nation guilty of internal or external misconduct.
Roosevelt's corollary to the Monroe Doctrine justified subsequent U.S.
intervention in Caribbean states during the administrations of Presidents William
Taft and Woodrow Wilson.
In the 1920s, and especially in the 1930s, the U.S. reduced the doctrine's
scope by favoring action in concert with the other American republics. This
emphasis on Pan-Americanism continued during and after World War II with the
Act of Chapultepec (1945) and the Rio Pact (1947), which declared that an attack
on one American nation was an attack on all. The formation of the Organization
of American States (1948) was designed to achieve the aims of the Monroe
Doctrine through Pan-Americanism. Subsequently, however, fear of communism
in Latin America prompted the U.S. to return to unilateral actions against
Guatemala (1954), Cuba (1961), and the Dominican Republic (1965), without
consulting its Latin American allies.
As a component of foreign policy, the Monroe Doctrine has had
considerable effect and has had strong support in the U.S., in part because it
promoted U.S. interests. The doctrine has served other American nations too,
particularly because it asserts their right to independence. Because the doctrine
as originally formulated made no clear distinction between the interests of the
U.S. and those of its neighbors, however, the U.S. has used it to justify
intervention in the internal affairs of other American nations. Given growing U.S.
anxiety about the unstable politics of Latin American countries, intervention has
been especially prevalent and controversial in the 20th century.