South Africa has largely decided to align itself with countries who act against the US interest and there is also a not insignificant sentiment against American intervention / involvement in other countries ("empire").

This is what withdrawal looks like. Assistance often comes with strings attached.

In my view, the withdrawal by America of intervention and support of liberal democracy around the world would be a detriment all around, but this is apparently what the American voter and many people from other countries prefer. That means in many cases throwing out the baby with the bathwater, so to speak.