The Treaty of Amity and Cooperation in Southeast Asia (TAC) was established in 1976 and embodies universal principles of peaceful coexistence and friendly cooperation among States in Southeast Asia. It is a legally-binding code for inter-state relations in the region and beyond. The Treaty has been amended three times, in 1987, 1998, and 2010, respectively, to allow for accession by states outside Southeast Asia as well as for regional organisations whose members are sovereign states, among others. As of October 2024, there are 55 High Contracting Parties to the TAC.