In the second half of the twentieth century, many Latin American nations began to transition from military dictatorships to democracies. Populist leaders tapped into the energy of the working classes and took control in many places. The United States continued its involvement in Latin America as the Cold War accelerated. In the 1970s, military dictatorships took control of many Latin American countries, but democracy eventually returned in most places. The United States inserted itself into Central American and Caribbean commerce and governance in the early twentieth century. It intervened more than thirty times before 1933, at which point President Franklin Roosevelt adopted the Good Neighbor Policy, which called for an end to armed U.S. intervention in Latin America.