The partners didn’t want to establish strong trade ties because of national animus between their peoples stemming from WW2 and regional security concerns, not because China is an unreliable trading partner. From what I’ve read, China is actually a very reliable trading partner and generally asks a lot less of countries than the US does. Obviously that’s how they attempt to gain influence and leverage in US spheres of influence longer term to make larger asks, but most politicians only think of short term consequences.

And national animus can change significantly over time. Just look at where US and Vietnam are (or were, prior to tariffs).

Lesson I learned doing business with PRC over the decades: if you're not family, then you are an enemy. If you're not Han, then you're not human...