The following article presents as basic objective, the approach to hemispheric security in America from three important historical moments: the Cold War, post-Cold War and the current period. In an introductory section, there will be a conceptual approach to security in the light of some authors in international relations and propose a suitable definition of it. Subsequently, there will be a brief historical overview of the regional security system during the Cold War, post-Cold War and the present, reflecting the latter effect on the present and future prospects of the TIAR and the OAS, the arms race ahead particularly in South America, and the current situation of drug trafficking and organized crime in Mexico.