[JonPreston]

Not so fast, Neocon. This war is the result of NATO expansion, first and foremost. The case has been laid out for anyone without an ingrained blood lust to understand. If you choose to ignore it, that’s fine, but remember; your old politics are coming to a rapid end. We simply ran out of money, and in your case, common sense.

[Bruce Campbells Chin]

No, this war is the result of Putin's decades old ass-ache over the dissolution of the Soviet Union, and desire to reconstitute it by force if necessary. That's it.

NATO expansion affected only the timing, because once a country joins NATO, invasion becomes much more risky for Russia. Other than preventing Russian expansion, a country joining NATO had zero impact on Russia.