Monroe Doctrine

The Monroe Doctrine is a major United States foreign policy position. It opposes any foreign interference in the Western Hemisphere. This policy was originally aimed at stopping European colonialism in the Americas. The doctrine states that any intervention in the political affairs of the Americas by foreign powers is a hostile act against the U.S.

This idea became a central part of American grand strategy during the 20th century. It helped define how the United States viewed its relationship with the rest of the world.

The doctrine works by dividing the world into two distinct spheres of influence. One sphere is the "New World," which includes the Americas. The other sphere is the "Old World," which refers to Europe. The policy asserts that these two worlds must remain separate. The United States promised not to interfere with existing European colonies in the Americas. In return, the U.S. would not meddle in the internal affairs of European countries. This was intended to prevent new colonization efforts among the newly independent Spanish American republics.

President James Monroe first articulated this doctrine on December 2, 1823. He shared these ideas during his seventh annual State of the Union Address to Congress. While it is named after him, the document was actually written chiefly by John Quincy Adams. Adams was the Secretary of State at the time. The doctrine was born during a period of great change in the Americas. Many Spanish colonies were either achieving or were very close to achieving their independence.

The U.S. wanted to ensure these new sovereign states were not re-colonized by European powers.

Early in its history, the United States lacked the strength to enforce the doctrine. The nation did not have a credible navy or a large army. Because of this weakness, many colonial powers largely disregarded the proclamation. For many years, the United Kingdom was actually the nation that enforced the doctrine. The British used its powerful Royal Navy to maintain its own policy known as Pax Britannica. Britain wanted to protect its ability to trade with the Americas. If European powers re-colonized the region, British access to those markets might be cut off by Spanish mercantilist policies.

History shows that the doctrine was ignored several times during the 19th century. In 1833, the British reasserted sovereignty over the Falkland Islands. The United States took no action, which caused some suspicion in Latin America. Later, between 1838 and 1850, the Río de la Plata in Argentina was blockaded by French and British navies. Again, the U.S. did not intervene. A major violation occurred in 1862 when French forces under Napoleon III invaded and conquered Mexico.

The United States could not stop this intervention because it was occupied with the American Civil War.

As the United States grew more powerful, the doctrine changed in its application. In 1845, President James K. Polk argued that the doctrine should support American western expansion. This was often linked to the idea of "manifest destiny." By the beginning of the 20th century, the U.S. was able to successfully enforce the doctrine itself.

Many different U.S. leaders have invoked the doctrine over the years. These include Ulysses S. Grant, Theodore Roosevelt, John F. Kennedy, Ronald Reagan, and Donald Trump.

In the 20th century, the way people understood the doctrine began to shift. After 1898, lawyers and intellectuals reinterpreted it to promote multilateralism. Multilateralism is the idea of many countries working together on shared goals. In 1933, President Franklin D. Roosevelt reaffirmed this new view. He helped co-found the Organization of American States to encourage cooperation in the hemisphere.

Today, the doctrine is still a subject of debate. It is frequently denounced, reinstated, or reinterpreted by different leaders and nations.