What: an expression of the post-1812 nationalism energizing the U.S. Proved to be the most famous of the long-lived offspring of that nationalism. Might have been called the Self-Defense Doctrine. Where & When: Incorporated into President Monroe's annual message to Congress in 1823. Its two basic features were:(1) Non-Colonization (2) Non-Intervention. Colonization's era had ended and England and other foreign powers needed to keep their monarchial systems out of the U.S. Old World powers could not gain anymore settlements. The U.S. would not intervene in the Greeks war for independence, and the U.S. does not need help from other countries. Significance: Gave vent to patriotism, but deepened the illusion of isolationism. Many Americans falsely concluded that the Republic was isolated from the European dangers because it wanted to be. Monroe, it seemed, had warned the Old Powers to stay away