In their relations with one another, the ASEAN Member States have adopted the following fundamental principles, as contained in the Treaty of Amity and Cooperation in Southeast Asia (TAC) of 1976:

Mutual respect for the independence, sovereignty, equality, territorial integrity, and national identity of all nations; The right of every State to lead its national existence free from external interference, subversion or coercion; Non-interference in the internal affairs of one another; Settlement of differences or disputes by peaceful manner; Renunciation of the threat or use of force; and Effective cooperation among themselves.

(Source: www.asean.org)