The ASEAN Declaration or Bangkok Declaration is the founding document of Association of Southeast Asian Nations (ASEAN). It was signed in Bangkok on 8 August 1967 by the five ASEAN founding members, Indonesia, Malaysia, Philippines, Singapore, and Thailand as a display of solidarity against communist expansion in Vietnam and communist insurgency within their own borders. It states the basic principles of ASEAN: co-operation, amity, and non-interference. The date is now celebrated as ASEAN Day.
Prior to the declaration, the five Southeast Asian states struggled to contain communist influence. At the time, the Filipino government struggled to give amnesty to former Hukbalahap militants, who staged an armed conflict in Luzon during the 1950s that almost led to the collapse of the central government. Conflict between the Indonesian military and the increasingly influential Indonesian Communist Party ended in late-1965 with the subsequent transition to Suharto's "New Order" that was staunchly anti-communist in contrast to previous president, Sukarno's increasingly communist-aligned administration. The Malaya was busy fighting communists during the Malayan Emergency.
Communism also led to the idea of merging the Federation of Malaya, Sarawak, Singapore, and North Borneo into one entity, which had the intention of eliminating the possibility of Singapore falling into communism.