Five-Power Defence Arrangements headed by the UK starting from 1971. In addition, there were some bilateral or trilateral border security agreements and defence links among selected ASEAN states. There was no region-wide security cooperation in the Asia-Pacific in the cold war period. It remains to be noted that for Southeast Asian security in the cold war, ASEAN took an active role in resolving conflicts. Basic principles and approaches in security cooperation were developed; these included notably the ASEAN way and the Treaty of Amity and Cooperation in Southeast Asia.