John Joseph Mearsheimer (an American political scientist and international relations scholar, who belongs to the realist school of thought. He is the R. Wendell Harrison Distinguished Service Professor at the University of Chicago. He has been described as the most influential realist of his generation https://en.wikipedia.org/wiki/John_Mearsheimer) wrote: " THE WAR in Ukraine is the most dangerous international conflict since the 1962 Cuban missile crisis. Understanding its root causes is essential if we are to prevent it from getting worse and, instead, to find a way to bring it to a close. There is no question that Vladimir Putin started the war and is responsible for how it is being waged. But why he did so is another matter. The mainstream view in the West is that he is an irrational, out-of-touch aggressor bent on creating a greater Russia in the mould of the former Soviet Union. Thus, he alone bears full responsibility for the Ukraine crisis.

But that story is wrong. The West, and especially America, is principally responsible for the crisis which began in February 2014. It has now turned into a war that not only threatens to destroy Ukraine, but also has the potential to escalate into a nuclear war between Russia and NATO..." (https://www.economist.com/by-invitation/2022/03/11/john-mear...) You can also check this documental by Oliver Stone: https://www.youtube.com/watch?v=yxau6qeWZ4w More references: "Russia's Ukraine invasion may have been preventable" https://www.msnbc.com/opinion/msnbc-opinion/russia-s-ukraine... "Putin’s Criminal Invasion of Ukraine Highlights Some Ugly Truths About U.S. and NATO" https://theintercept.com/2022/03/07/ukraine-russia-nato-koso... "Russian hostility 'partly caused by west', claims former US defence head" https://www.theguardian.com/world/2016/mar/09/russian-hostil...