In May 1965, when U.S. troops landed in the Dominican Republic, President Lyndon Johnson pronounced his “Johnson Doctrine,” declaring that the United States would never again permit the establishment of a Communist regime in the Western Hemisphere. Although the Dominican intervention marked the first armed, overt U.S. intervention in Latin America in over three decades, the intervention and the Johnson Doctrine did not mark a signal departure in inter-American relations. Since the late nineteenth century, the United States has maintained a sphere of influence within the Western Hemisphere, exercising predominant influence in the region and limiting the freedom of action of Latin American nations.