From the Monroe Doctrine of 1823 to the current Obama Doctrine, presidential doctrines have dominated American foreign policy. A presidential doctrine highlights the key foreign affairs objectives and positions of the United States set by a president. Many of the country's major foreign policy successes or disasters can be explained by tracing the doctrines of current or previous presidents and analyzing their evolution and possible impact on world events. Once a presidential doctrine has been established, it has a life of its own. This is explained by the military resources and human capital involved in implementing these doctrines. Future presidents often feel obligated to comply, or discover that doctrinal change can only be accomplished through incremental changes over a period of years. For this reason, presidential doctrines outlive their creators and some will affect American foreign policy for centuries to come. This essay will focus on the Reagan administration which spanned from January 1981 to January 1989. When Reagan became president, he had only one well-defined doctrine. foreign policy goal: to contain the Soviet Union, or “the evil empire,” as he once called it. Above all, he wanted to prevent the expansion of the USSR and prevent other non-communist countries from becoming communist. In the past, American presidents have used a theory called the “domino theory” to justify the need for intervention in the world. The theory assumed that if one state in one region fell under the influence of communism, then surrounding countries would follow in a domino effect. Before the Reagan administration, the United States had already made several attempts to combat the spread of C...... middle of paper ...... individual states, thus ending the Cold War. Reagan's leadership and the relationship he built with Gorbachev paved the way for a peaceful resolution to the Cold War. Through his foreign policy, Reagan sought to achieve the transformative goal of “peace through strength.” But while Reagan's military budget expansion and warlike rhetoric were significant, his vision would not have come to fruition without an atrophying Soviet economy and Gorbachev's rise to power in 1985. braunwarth_reader/sec20.htm http: //en.wikipedia.org/wiki/Reagan_Doctrine http://www.cato.org/publications/policy-analysis/us-aid-anticommunist-rebels-reagan-doctrine-its-pitfalls http http://www.thoughtleader .co.za/joncayzer/2011/02/16/ronald-reagan-at-100-the-legacy/ http://www.hks.harvard.edu/m-rcbg/CSRI/publications/workingpaper_16_ruggie.pdf