>> Russia stated that Ukraine joining NATO would start a war. The US began that process knowing Russia's reaction. Russia did what it said it would do.
> This has nothing to do with reality.
> ...
> Russia did not threaten anyone with war over the prospect of NATO membership.
As much as I hate Putin and his regime, we have to admit Russia did indeed said that it views the NATO expansion as an existential threat.
From Putin's 2007 Munich speech [1]:
> It turns out that NATO has put its frontline forces on our borders, and we continue to strictly fulfill the treaty obligations and do not react to these actions at all. I think it is obvious that NATO expansion does not have any relation with the modernization of the Alliance itself or with ensuring security in Europe. On the contrary, it represents a serious provocation that reduces the level of mutual trust.
The speech obviously did not make a direct threat, this is a political speech after all, but the message was crystal clear for most, take for example the letter [2] Burns (US ambassador to Russia from 2005 to 2008) sent after the Munich's speech to Condoleeza Rice in which Burns warned of serious consequences arising from NATO’s eastward expansion to include Ukraine and Georgia:
> Ukrainian entry into NATO is the brightest of all redlines for the Russian elite (not just Putin). In more than two and a half years of conversations with key Russian players, from knuckle-draggers in the dark recesses of the Kremlin to Putin’s sharpest liberal critics, I have yet to find anyone who views Ukraine in NATO as anything other than a direct challenge to Russian interests. At this stage, a MAP offer would be seen not as a technical step along a long road toward membership, but as throwing down the strategic gauntlet. Today’s Russia will respond. Russian-Ukrainian relations will go into a deep freeze. . . . It will create fertile soil for Russian meddling in Crimea and eastern Ukraine. (letter to Condoleeza Rice, February 2008)
[1] https://securityconference.org/en/publications/books/selecte...
[2] https://en.wikipedia.org/wiki/2007_Munich_speech_of_Vladimir...
[edit]: formatting