We can't know, it's alt-history speculative wankery. But what we can know is that the latter left the former with very few options.

You have very interesting priors, I must say.

Yes. Reestablising soviet empire was Putins life long project from the moment he gained significant power. Vibes of it are easy enough to notice in his speeches predating '08

Those are not words of a man in fear. Those are the words of a man with a dream.

NATO went east in 1999, which was before Putin. '08 was when the war in Georgia took place.

You might want to look up who Russia’s head of government (not chief of state) was in 1999.

Though, on the other hand, the process of NATO expansion into the former Iron Curtain (beyond German unification) actually started in 1991, almost immediately after the fall of the USSR, with requests from a number of ex-Warsaw Pact, including ex-Soviet, republics for an onramp to NATO (including, it might be noted, the Russian Federation, which was also one of the initial members, in 1994, of the NATO-onramp Partnership for Peace program. Which is among the very many reasons that the recent debate about a supposed 1989 commitment to not expand NATO into former Warsaw Pact territory is nonsense: even if such an informal non-treaty assurance was binding, and inherited from the USSR by Russia, Russia’s subsequent active and formal participation in the NATO expansion process would have repudiated it, in any case.)