Just like Japan? South Korea? Taiwan? Singapore? Or on the other side, pretty much the entire Middle East?

Collectivist Asian cultures can definitely manage separation of powers and democracy.

I always wonder whether Japan, Korea, Taiwan would be able to preserve separation of powers without US support. I feel like if US one day declines in power and won't be able to support then, they would fall into autocracies pretty quickly.

You could say the same about a lot of non-Asian countries, though. Australia/NZ for a start, but I can imagine much of Eastern Europe too.

well, history in general shows autocracy flourishes whether or not the individual or the collective is primary, not sure you can claim a correlation there