What is the Monroe Doctrine, and why does Trump want to ‘reassert’ it?

First established in 1823, the Monroe Doctrine has been used to justify American dominance and influence over the western hemisphere, particularly in Latin America.

One of the central pillars of U.S. President Donald Trump’s new national security strategy is a plan to update a more than 200-year-old foreign policy statement known as the Monroe Doctrine.

“After years of neglect, the United States will reassert and enforce the Monroe Doctrine to restore American preeminence in the Western Hemisphere, and to protect our homeland and our access to key geographies throughout the region,” the strategy document unveiled last week states.

The document goes on to lay out a “‘Trump Corollary’ to the Monroe Doctrine” that prioritizes American-led cooperative efforts to combat mass migration, drug trafficking and “hostile foreign incursion or ownership of key assets.”

The strategy marks the latest evolution of the Monroe Doctrine, which has been held up as either an argument for peace and non-intervention or justification for American imperialism — depending on how U.S. presidents interpreted it.

The implications of the doctrine were particularly felt in Latin America, where Trump is currently seeking an array of strategies — from military action near Venezuela to financial aid for Argentina — to exert U.S. influence.

Here’s what to know about the Monroe Doctrine and how it has evolved over the years.

U.S. President James Monroe delivered what became known as the Monroe Doctrine during a State of the Union address to Congress in 1823.

The text, developed by his secretary of state John Quincy Adams, asserted that countries in the western hemisphere — identified as North and South American continents — “are henceforth not to be considered as subjects for future colonization by any European powers.”