2014- “The reality is that, after two decades of eastward Nato expansion, this crisis was triggered by the west's attempt to pull Ukraine decisively into its orbit and defence structure, via an explicitly anti-Moscow EU association agreement. Its rejection led to the Maidan protests and the installation of an anti-Russian administration – rejected by half the country – that went on to sign the EU and International Monetary Fund agreements regardless.”

Doing a re-dig and this jumped out. Eric C and the Maidan massacre is the inflection point.

https://www.theguardian.com/commentisfree/2014/apr/30/russia-ukraine-war-kiev-conflict