The Monroe Doctrine was a U.S. foreign policy statement made by President James Monroe before Congress in 1823. At its core the Monroe doctrine asserted the principle that the Western Hemisphere was closed to further European colonization. Additionally, the doctrine stated that European forms of government were unsuited to the Western Hemisphere and that the United States would view attempt to establish those forms of government as a threat to U.S. security. The remaining two tenets of the doctrine stated that the U.S. would not interfere with European affairs or interfere with existing colonies in the Western Hemisphere, neither of which the United States had any intention of doing.

The roots of the Monroe Doctrine began with the Napoleonic Wars.  The Napoleonic Wars engaged the major powers of Europe for a protracted period of time, on and off from 1800 until 1815. European preoccupation with internal affairs allowed Latin American colonies to follow the example of the American Revolution and throw off the chains of colonial rule. Simón Bolívar and José de San Martín led many of these revolutions between 1808 and 1826. The United States supported these uprisings for two reasons: first, the revolutions followed the American example of self-government, and second, and more importantly, because the Latin American revolutions would leave relatively weak republics since the new governments would not have European support and the U.S. hoped to dominate these weak governments without involving conflict with European colonial powers. The creation of relatively weak Latin American republics also emboldened those who favored Manifest Destiny by providing the possibility that that U.S. might eventually extend not only from coast to coast but potentially from pole to pole.  (Historical Note: The United States was very concerned with Russian expansion on the west coast of North America. The Adams-Onís Treaty of 1819, also known as the Transcontinental Treaty or the Florida Purchase Treaty, not only ceded Florida to the United States, but also it established the boundary between Spanish and U.S. territory west to the Pacific. Under the terms of the treaty, Spain ceded its claims of the Oregon Territory to the U.S., thus enhancing the American claim and potentially bringing the U.S. into conflict with Russia.)

The U.S. support Latin American revolutions because they would leave relatively weak Latin American republics- since the new governments would not have European support- and the U.S. hoped to dominate these weak governments without involving conflict with European colonial powers.

Following the defeat of Napoleon in 1815, the United States was concerned that European countries would begin to reclaim the colonies that rebelled during the Napoleonic Wars. To protect the western hemisphere from a new wave of European meddling, the United States began to devise a way to deter European recolonization. Additionally, the U.S. found an ally in one European power, Great Britain, that did not want to see a recolonization of Latin America by European countries because the new, independent Latin American governments could freely trade with Britain.  Thus, the British Foreign Secretary Canning proposed to the Monroe administration that Great Britain and the United States jointly announce what would subsequently become the essence of the Monroe Doctrine.

To protect the western hemisphere from a new wave of European meddling the United States began to devise a way to deter European re-colonization.

However, Secretary of State John Quincy Adams (co-author of the Monroe Doctrine) thought that a joint declaration would appear to show weakness on the part of the U.S. His fear was that the world would see the U.S. as unable to enforce the provisions of the Monroe Doctrine without the support of the British Navy. Adams knew that the U.S. was incapable of enforcing the Monroe Doctrine without the assistance of the British Navy, but he also knew that that Great Britain was one-hundred percent behind the doctrine. In the waning days of the Era of Good Feeling characterized by intense nationalistic sentiment, Adams’ ploy to go it alone played well with the American people and their desire to emphasize American might and power.

Adams knew that the U.S. was incapable of enforcing the Monroe Doctrine without the assistance of the British navy but also knew that that Great Britain was one-hundred percent behind the doctrine.

In fact, there was some justification for this position. Latin American countries had incurred significant debt that they owed to European nations. There was fear that these European nations might try to forcibly recover those debts. If that occurred, European political strength would grow in those countries while U.S. influence would decline. The United States did intervene in the internal affairs of several Latin American countries utilizing the “big stick” philosophy as the enforcement mechanism for the Roosevelt Corollary. Latin American countries at first welcomed U.S. protection from European intervention but became increasingly suspicious of U.S. intentions over time.

William Howard Taft was elected president in 1908 and continued to use the Roosevelt corollary to the Monroe Doctrine to support his foreign policy initiatives dubbed “Dollar Diplomacy.”  Dollar diplomacy encouraged U.S. businesses to invest heavily in Latin American countries with the tacit understanding that those investments would be protected by U.S. intervention if necessary. As the investments of U.S. companies grew, they would increasingly become an indispensable part of the economy of each Latin American country which would increase American clout to the point that U.S. business interests might dictate the policies of independent nations.  The Roosevelt corollary was officially eliminated during the presidency of Franklin Roosevelt who attempted to establish a “good neighbor” policy with Latin American countries.

The United States did intervene in the internal affairs of several Latin American countries utilizing the “big stick” philosophy as the enforcement mechanism for the Roosevelt Corollary.

Though not specifically attached to the Monroe Doctrine, the Truman and Eisenhower Doctrines and the Marshall Plan of the 1940s and 1950s have certain similarities. Both the Truman and Eisenhower Doctrines were designed to dissuade attempted takeovers of European and Middle Eastern countries by communist forces (either internal or external) by threatening the use of American economic and military power. Certainly the power of the U.S. in the twentieth century was far more potent than during the era of the Monroe Doctrine. Similarly, the Marshall Plan was designed to pump money into Europe to rebuild the war-torn nations and stabilize them so that they would be less likely to elect leftist governments.

Thus the Monroe Doctrine, originally perceived as a means to remain committed to Washington’s policy of neutrality and non-involvement in European affairs, eventually morphed into a means to rationalize U.S. intervention to protect American interests in Latin America. Alluded to but sparsely used in the nineteenth century, the Monroe Doctrine nevertheless gained a largely unjustified reputation in the American mind for intimidating European nations and keeping them out of the Western Hemisphere.  Its power was more psychological than real.