The events and processes that have taken place in the last decade in South America have given way to one of the most interesting regional phenomena under a global crisis and within a changing world order. From the traditional status of Washington ́s backyard and reign of economic and political stability, South America has increasingly turned into a region marked by a heterodox development in the light of other dominant regional tendencies of development-the European Union, NAFTA and the Asia Pacific. The political economic nature of the new South American regionalism (NSAR) is far from echoing the dominant interpretations about it, which reflects the major regional projects today. Given the reach and scope of the existing literature on the topic of the NSAR, there is an important gap concerning its academic exploration in relation to its nature of development, political economic complexity, challenges and orientations. In this sense, this book explores, from a wider and pluralist political economic perspective, the developmental dimensions of the NSAR within a changing hemispheric and world order in transformation. It analyses a set of specific debates: regionalism in the Americas then and now; social and economic development and regional integration; and organized crime, intelligence and defence. An in depth and critical reflection on the complex and heterogeneous path of regionalization taking place in South America from different perspectives and in key issues of regional development.