From the Overview: "The Association of Southeast Asian Nations (ASEAN) is Southeast Asia's primary multilateral organization, a 10- member grouping of nations with a combined population of 650 million and a combined annual gross domestic product (GDP) of around $2.8 trillion in 2019. Established in 1967, it has grown into one of the world's largest regional fora, representing a strategically important region straddling some of the world's busiest sea lanes, including the Straits of Malacca and the South China Sea. Taken collectively, ASEAN would rank as the world's fifth-largest economy and the United States' fourth-largest export market. [...] ASEAN is a diverse and informal organization. Two of its core operating principles are consensual decisionmaking and noninterference in the internal affairs of its members. Some observers argue that this style constrains ASEAN from acting strongly and cohesively on important issues. Others argue that these principles--dubbed the 'ASEAN Way'--promote regional stability and ensure that the group's members continue to discuss issues where their interests sometimes diverge. The principle has been tested in 2021, as ASEAN seeks to address the crisis that has followed the Burmese military's February 1 coup d'etat."
CRS In Focus, IF10348
Congressional Research Service: https://crsreports.congress.gov/