Setting up the Weimar Republic after WW1 didn't go so well, then the aftermath of WW2 there were decades of east+west Germany. I don't see that as a positive example of a foreign power setting up a government.
The USA side was much better than the USSR side...
The Weimar Republic wasn't set up by the Entente and not going to war with the Soviet Union to liberate East Germany was, to put it mildly, a reasonable decision.