The politics of the US are very different from the 40's to 90's. Good luck explaining to the American public why a bunch of their kids need to go die defending the Taiwanese in 2024 unless you can base it in some cold hard economic reality.

The reason we supported them back in the 20th century is because the Red Scare was the big boogeyman of the time and we needed military bases and friendlies in that part of the world.