This chapter aims to provide a long-term perspective on the rise of the US to hemispheric hegemony in the Americas, and to discuss some of the consequences of such a rise in the second half of the twentieth century, in particular, those consequences which resulted in the genocidal repression by military and authoritarian rulers of their own countrymen in the Southern Cone during the 1970s and 1980s, and in Central America in the 1980s and early 1990s. While providing such a background, this chapter aims to be synoptic and not exhaustive. For further information and to test the general arguments presented here, readers are referred to an extensive literature that follows a continental scope of analysis,2 and monographs devoted to the study of relationships between the US and other countries in the Americas.3