The time after World War II changed the political map of Southeast Asia permanently. Indonesia declared its independence from the Netherlands in 1945, which they accepted just in 1949 after the War of Indonesian Independence. The Philippines became independent from the USA in 1946. The Federation of Malaya became independent from the United Kingdom in 1957 and in 1963 Malaysia was founded when Sabah, Sarawak and Singapore were added to the Federation. Indonesia did not accepted its new neighbour and started the Konfrontasi and also the Philippines raised a claim to Sabah. Singapore was expelled from the Federation in 1965 due to ideological differences and became an independent state. But despite all these conflicts representatives of the four states and of Thailand came together in Bangkok in August 1967 and founded the Association of Southeast Asian Nations with the Bangkok Declaration. Its main aims were and still are economic growth, social progress, sociocultural evolution and the protection of regional stability, but it was also founded as reaction against the Vietnam War and the Communism. In 1984 Brunei joined the ASEAN barely a week after gaining independence from the United Kingdom. Myanmar and Laos joined in 1997. In the same year the ASEAN was also hit hard by the Asian financial crisis. Cambodia joined the community as last new member in 1999. In 2007 the ASEAN- Charter was signed, which turned the ASEAN into a legal entity and aimed to create a single free-trade area with the purpose of moving closer to an EU-style community. Today the ASEAN is an active global partner and works together with other parts of the World to promote World peace and stability.
To commemorate the 48th and 50th anniversary of the ASEAN its member states issued joint stamps in 2015 and 2017 (without Brunei). I have all stamps from 2015, but still miss some stamps from 2017. If anybody can help me to get the stamps from Cambodia, Myanmar or Laos please write it in the comments.