Japan: Commies takes power somehow. Perhaps civil war in 1920's. Thailand: Commies takes power during Cold War. Malaysia: Very different decolonisation. And include Brunei too so you are similarly abolished Brunei monarchy. Bhutan: India invades the country in some point. Jordan: Revolution breaks out soon after Abdullah I's assassination and Jordan Arab Republic is founded. Or then make United Arab Republic more stable and it annexes the country. Saudi-Arabia: This is quiet tricky. Probably best way is some kind of Islamic revolution like in Iran. Oman: Revolution. Small Gulf Emirates: Quiet tricky but probably some kind of Islamic/Arab Socialist revolution is only way. Kuwait is quiet easy. Western nations just accepts that Iraq annexes Kuwait.