You really need to be careful generalizing the whole Asia region to fit your narrative. S. Korea was already a bit culturally ethno-nationalist not because of reasons like 'racism' or something like Western populist politics, but because of the more complex history of being colonized and almost assimilated by Japan. And diplomatically S. Korea's has always been pro-US for pragmatic reasons (military protection) and would probably stay that way for some time. (That doesn't mean there isn't any anti-US sentiment among citizens, it's just that it hasn't been materialized into anything significant in actual global relations.)
Trump, despite tricking a few LARPers into thinking he had some kind of great agenda was just a TV show host. He was about as likely to rebuild the US in some kind of new image as a televangelist is in bringing the kingdom of god to earth.
"In reality, they're not after me, they're after you. I'm just in the way"
well after Modi, and in the time since it's been adopted by Netanyahu as well. I often wonder why these people are called "nationalists"...