This chapter provides some of the conflicts, tensions and security pressures that have threatened to undercut stability in South-East Asia, or parts thereof. It reviews the approaches—individual, bilateral, multi-country, regional—that member countries of the Association of Southeast Asian Nations have adopted in response. The chapter shows that having emphasized for several years the particular relevance of transnational security threats, regional governments have re-focused attention on conventional security threats, primarily ones that are linked to the People’s Republic of China’s rise and the South China Sea conflict. The Security Studies literature has conventionally identified multiple security referents and sectors and various sources of threat. South-East Asia’s territorial disputes are generally a legacy of colonialism as European powers re-ordered political space when they dominated the region’s international relations. Intraregional suspicions, for instance, are widely understood to have been a barrier to multilateral intelligence exchanges among South-East Asian countries.