[mytailorisrich]

When it comes to China I don't think that the aftermath of WWII are key.

The events within China were ongoing and had their roots in the 18th and 19th centuries, as per previous comments, and they are still ongoing.

Japan had invaded in earnest in 1937. That in itself was a consequence of what had been going on for more than a century in both Japan and China. WWII's impact is that suddenly the US was happy to help the RoC and even the communists against Japan. The US did shorten the Japanese invasion of China but I don't think Japan could have prevailed anyway because they were to swallow too much.

Then the US supported Korea and Japan in the aftermath of WWII in their global play against communism and the USSR but that did not have much impact on China.

China is the natural and historical super-power in (East) Asia and there is nothing the US can do for or against that on any relevant historical timescale.

What WWII did is making the US the main power in East Asia. That's neo-imperialism, really, and again linked to the temporary weakness of China. This can be useful for some countries in order to balance Chinese influence but, again, in the long run the overwhelming power will remain China. However one looks at it a 300 million people country on the other side of the world cannot outdo a 1.4 billion country next door in the long run.