Abstract
Throughout the twentieth century and more especially since the end of the Second World War, the United States has successfully established itself as a key actor in the international scene. Since 1945, the United States has frequently proved its ability to change the course of history. Most of the superpower's actions, either diplomatic or military, show a willingness to play a leading role on the international scene. Indeed, they intervened in a lot of countries since 1945: Korea, Cuba, Vietnam, Somalia, and more recently Afghanistan and Iraq.
South America has also been a source of interest for the different U.S. governments for a long time. Back in 1823, the President Monroe warned the European countries that any attempt to colonize a part of America would be severely repressed by the U.S. Known as the "doctrine Monroe", he also mentioned that the United States promises not to intervene in Europe. This doctrine is important in the sense that it has set the biggest outlines of the U.S. foreign policy during the twentieth century and keeps, at a certain level, impregnating its today's foreign policy. Historically, Latin America has always been of great importance to the United States. The U.S., still up to recently, has been the major partner in the region. Latin America provided an important outlet for U.S. buyouts, particularly in the field of oil.
