The first promise made by the Monroe Doctrine mirrored the isolationist perspective that Monroe shared with many of his predecessors, including George Washington and Thomas Jefferson. In his address, Monroe declared that "In the wars of the European powers in matters relating to themselves we have never taken any part, nor does it comport with our policy to do so." He went on to state that although the United States could be provoked to war when its liberties were jeopardized, it would not become involved with any European wars as long as they had nothing to do with the well-being of the country.
The Monroe Doctrine stated that the American continents were closed to European colonization. However Spain still governed several New World colonies, such as Bolivia, Cuba and Puerto Rico. Monroe assured Europe that the United States would respect those existing colonies, but this did not mean the United States was comfortable or content with these bastions of European imperialism. In fact, the same year that he put forth his doctrine, Monroe approached Spain with a request to annex Cuba. He believed all such matters should be settled by mutual agreement, not by military might.
While Monroe respected the right of European nations to control their present colonies, he stated that the United States would view any further attempts at colonization as acts of aggression. In particular, he warned Spain about trying to reconquer the newly independent Latin American nations: "But with the Governments who have declared their independence and maintain it ... we could not view any interposition for the purpose of oppressing them, or controlling in any other manner their destiny, by any European power in any other light than as the manifestation of an unfriendly disposition toward the United States."
Although Monroe did not make the Latin American nations protectorates of the United States, he did promise the European nations that further colonization would be grounds for military action.
The Monroe Doctrine promised Europe that the United States would follow its own rules. Monroe did not prohibit European colonization for the purpose of eliminating competition; rather, he believed that the Latin American nations deserved the same respect the United States had fought to win less than 50 years before. Whereas Spain, France and Great Britain refused to recognize the former colonies as independent countries, the United States had already acknowledged their sovereign status. Monroe promised "to leave the parties to themselves, in hope that other powers will pursue the same course."