Southeast Asia is central both in terms of geopolitics and the rivalry between the two megaprojects, focused on sinocentric and japanese(american)centric globalization. In terms of global and regional leadership, the region is becoming a competitive area for "control" of the strategic landscape between the PRC and the USA. The article is devoted to the regionalization processes through the prism of the theory of the formation of mega-regional blocs. The purpose of the article is to analyze the approaches of Japan, India and the USA to the formation of mega-partnerships in Southeast Asia, as well as to identify the main competitive advantages of the studied initiatives for the Southeast Asian countries.