This thesis asks why the North American Aerospace Defense Command (NORAD) continues to exist and remain relevant in the defence of North America following the disappearance of the threat of the Soviet Union at the end of the Cold War. This thesis argues that NORAD’s binational nature is key to understanding the command’s continued role in continental defence. By employing the international relation theories of functionalism and neoliberal institutionalism as a lens of analysis to understand binational defence cooperation, NORAD’s origins as a binational defence command tasked with the air defence of North America, and its acquisition of its responsibilities for drug interdiction, the continental interior, and for maritime warning are analyzed. NORAD’s longevity and continued relevance can be attributed to the command’s binational nature, which has allowed the command to focus on and institutionalize specific functional-technical solutions to select issues of mutual concern in continental defence and security for Canada and the U.S. / May 2016