Regime

Thailand

 -Parliamentary system

-Constitutional monarchy

-Military dictatorship

-Unitary state

-Military junta

Laos

-Republic

-Unitary state

-Communist state

Cambodia

-Unitary state

-Constitutional monarchy

-Elective monarchy

-Parliamentary system

-One-party state

Myanmar

-Parliamentary system

-Presidential system

-Parliamentary republic

-Unitary state

Vietnam

-Communist state

-Unitary state

-One-party state

-Socialist state

Philippines

-Republic

-Presidential system

-Parliamentary republic

-Unitary state

Malaysia 

 -Democracy 

-Constitutional monarchy

-Parliamentary system

-Elective monarchy

Brunei

-Absolute monarchy

-Constitutional monarchy

-Unitary state

Singapore

-Unitary state

-Parliamentary republic

Indonesia

-Democracy

-Presidential system