Southeast Asia

Southeast Asia is a region of the world on the Asian landmass and nearby island nations in the Pacific Ocean. Different organizations define have different descriptions of its scope. Perhaps most definitive is membership of the key regional alliance, Association of Southeast Asian Nations (ASEAN). Countries typically included in the region are Indonesia, Malaysia, the Philippines, Singapore, Thailand, Brunei Darussalam, Vietnam, Laos, Myanmar and Cambodia.

State	ASEAN	US reporting
Indonesia	Yes	Yes
Malaysia	Yes	No
Philippines	Yes	No
Singapore	Yes	Yes
Thailand	Yes	Yes
Brunei Darussalam	Yes	No
Vietnam	Yes	Yes
Laos	Yes	Yes
Myanmar	Yes	No
Cambodia	Yes	Yes

U.S. government documents, especially those from the Vietnam War, exclude some of these countries. Myanmar/Burma is placed in South Asia.

The Southeast Asian Treaty Organization (SEATO) was created in the Cold War, but was never a viable organization, as was its presumed counterpart, the NATO|North Atlantic Treaty Organization (NATO).

Other than the Philippines, which was in the Southwest Pacific theater, these countries were part of the China-Burma-India theater in the Second World War.