Why did the European powers never conquer Thailand or China?

I've been told it was because they wouldn't let any of them be in control of fucking China, and they couldn't agree on how to share it.

>>1988102
same reason why the belgians became independent and not a part of france, why they didn't go to war against the ottomans, and siam was unmolested.
great powers stop shit getting done

>>1988167
This. Everyone wanted a piece of the pie so they just carved it up into spheres of influence.

>>1988102
Thailand was monarchy, its' colonisation was improper.
China wasnt conqured by Europeans because of resistance of USA.

I think Thailand was just too inhospitable to conquer, so much of it is remote jungle. Easier to just make deals with the reigning monarch. As for China, it was too big for anyone nation to control all of it, so they just snatched what they could for themselves and spent their time scheming against one another, which made them super vulnerable come World War 1 and that's why Japan was able to divest Germany of most of their East Asian holdings.