a part of US foreign policy that states that the US will act to protect its own interests in N and S America From the name of US President James Monroe, who first stated the policy in 1823. Culture The Monroe Doctrine is one of the most important policies in US history. Monroe said the US would oppose any new European attempts to control countries in the Americas but it would not interfere with European interests already there. The British, who were well established in the New World, supported this. President Theodore Roosevelt added in 1904 that the US might have to become involved in problems in other American nations. President Franklin Roosevelt, however, introduced the Good Neighbor Policy which said American nations should work together as equal partners. Though the US has been involved in some military and political actions in Latin America, this is still the official US policy.