Ronald Reagan was great, but it’s also true the USSR fell not under Reagan, but under GHWB, and the elder Bush managed it superbly. All conventional wisdom was that East Germany would have to be kept in the Russian sphere, definitely no NATO troops there. Bush insisted on and got 100% German reunification in NATO.
As for a posting here about Yeltsin, when hardline commie generals tried to stage a coup, Bush backed Yeltsin and prevented a possible return to the cold war.
Has Bush been reelected, as a 2 term president his accmplishments would be far more recognized.
It also helped that Helmut Kohl was the German leader back then.