This really depends on the context of how you are using it.
All such labeling is purely arbitrary.
If you are talking about the large scale mass as a continent than it is simply Asia.
However, any such mass can be discussed on smaller regional bias using terms like south East Asia. It gives geographical context to directional descriptions.
communism
Because it is in the part of Asia in the most South East Part
South Asia, Middle East, South-east Asia, East Asia, Central Asia
The 5 major regions of Asia are Southeast Asia, East Asia, Central Asia, South Asia, and Southwest Asia(also known as the Middle East).
the Yellow River
Indonesia
Thailand is in South East Asia, or SE Asia
South East Asia
describe why the moonsoon important for south and south-East Asia
describe why the moonsoon important for south and south-East Asia
No. That's why it's called south east Asia !
Indonesia