There are two major factors fuelling this crisis. The first was the ill-considered decision by the US in the 1990s to expand NATO after the collapse of the Soviet Union. The second is how Putin exploited NATO’s expansion closer to Russia’s borders to rally Russians to his side.

When a major conflict like Ukraine breaks out, journalists always ask themselves: “Where should I station myself?” Kyiv? Moscow? Munich? Washington? In this case, my answer is none of these. The only place to be for understanding this war is inside Russian President Vladimir Putin’s head. Putin is the most powerful, unchecked Russian leader since Stalin, and the timing of this war is a product of his ambitions, strategies and grievances.

But, with all of that said, America is not entirely innocent of fuelling his fires.

How so? Putin views Ukraine’s ambition to leave his sphere of influence as both a strategic loss and a personal and national humiliation. In his speech on Monday, Putin literally said Ukraine has no claim to independence, but is instead an integral part of Russia — its people are “connected with us by blood, family ties.” Which is why Putin’s onslaught against Ukraine’s freely elected government feels like the geopolitical equivalent of an honour killing.

Putin is basically saying to Ukrainians (more of whom want to join the European Union than NATO): “You fell in love with the wrong guy. You will not run off with either NATO or the E.U. And if I have to club your government to death and drag you back home, I will.”

This is ugly, visceral stuff. Nevertheless, there is a back story here that is relevant. Putin’s attachment to Ukraine is not just mystical nationalism.

In my view, there are two huge logs fuelling this fire. The first log was the ill-considered decision by the U.S. in the 1990s to expand NATO after — indeed, despite — the collapse of the Soviet Union.

And the second and far bigger log is how Putin cynically exploited NATO’s expansion closer to Russia’s borders to rally Russians to his side to cover for his huge failure of leadership. Putin has utterly failed to build Russia into an economic model that would actually attract its neighbours, not repel them, and inspire its most talented people to want to stay, not get in line for visas to the West. We need to look at both of these logs. Most Americans paid scant attention to the expansion of NATO in the late 1990s and early 2000s to countries in Eastern and Central Europe like Poland, Hungary, the Czech Republic, Latvia, Lithuania and Estonia, all of which had been part of the former Soviet Union or its sphere of influence. It was no mystery why these nations would want to be part of an alliance that obligated the U.S. to come to their defence in the event of an attack by Russia, the rump successor to the Soviet Union.

The mystery was why the U.S. — which throughout the Cold War dreamed that Russia might one day have a democratic revolution and a leader who, however haltingly, would try to make Russia into a democracy and join the West — would choose to quickly push NATO into Russia’s face when it was weak. A very small group of officials and policy wonks at that time, myself included, asked that same question, but we were drowned out. The most important, and sole, voice at the top of the Clinton administration asking that question was none other than the defense secretary, Bill Perry. Recalling that moment years later, Perry in 2016 told a conference of The Guardian newspaper:

“In the last few years, most of the blame can be pointed at the actions that Putin has taken. But in the early years I have to say that the United States deserves much of the blame. Our first action that really set us off in a bad direction was when NATO started to expand, bringing in Eastern European nations, some of them bordering Russia. “At that time, we were working closely with Russia and they were beginning to get used to the idea that NATO could be a friend rather than an enemy … but they were very uncomfortable about having NATO right up on their border and they made a strong appeal for us not to go ahead with that.”

On May 2, 1998, immediately after the Senate ratified NATO expansion, I called George Kennan, the architect of America’s successful containment of the Soviet Union. Having joined the State Department in 1926 and served as U.S. ambassador to Moscow in 1952, Kennan was arguably America’s greatest expert on Russia. Though 94 at the time and frail of voice, he was sharp of mind when I asked for his opinion of NATO expansion.

I am going to share Kennan’s whole answer:

“I think it is the beginning of a new cold war. I think the Russians will gradually react quite adversely and it will affect their policies. I think it is a tragic mistake. There was no reason for this whatsoever. No one was threatening anybody else. This expansion would make the founding fathers of this country turn over in their graves.

“We have signed up to protect a whole series of countries, even though we have neither the resources nor the intention to do so in any serious way. [NATO expansion] was simply a light-hearted action by a Senate that has no real interest in foreign affairs. What bothers me is how superficial and ill informed the whole Senate debate was. I was particularly bothered by the references to Russia as a country dying to attack Western Europe.

“Don’t people understand? Our differences in the Cold War were with the Soviet Communist regime. And now we are turning our backs on the very people who mounted the greatest bloodless revolution in history to remove that Soviet regime. And Russia’s democracy is as far advanced, if not farther, as any of these countries we’ve just signed up to defend from Russia. Of course there is going to be a bad reaction from Russia, and then [the NATO expanders] will say that we always told you that is how the Russians are — but this is just wrong.” It’s EXACTLY what has happened.

To be sure, post-Cold War Russia evolving into a liberal system — the way post-World War II Germany and Japan did — was hardly a sure thing. Indeed, given Russia’s scant experience with democracy, it was a long shot. But some of us then thought it was a long shot worth trying, because even a less-than-democratic Russia — if it had been included rather than excluded from a new European security order — might have had much less interest or incentive in menacing its neighbours. Of course, none of this justifies Putin’s dismemberment of Ukraine. During Putin’s first two terms as president — from 2000 to 2008 — he occasionally grumbled about NATO expansion but did little more. Oil prices were high then, as was Putin’s domestic popularity, because he was presiding over the soaring growth of Russian personal incomes after a decade of painful restructuring and impoverishment following the collapse of communism.

But across the last decade, as Russia’s economy stagnated, Putin either had to go for deeper economic reforms, which might have weakened his top-down control, or double down on his corrupt crony capitalist kleptocracy. He chose the latter, explained Leon Aron, a Russia expert at the American Enterprise Institute and the author of “Yeltsin: A Revolutionary Life,” who is now writing a book about the future of Putin’s Russia. And to both cover and distract from that choice, Putin shifted the basis of his popularity from “being the distributor of Russia’s newfound wealth and an economic reformer to the defender of the motherland,” Aron said.

And right when Putin opted for domestic political reasons to become a nationalist avenger and a permanent “wartime president,” as Aron put it, what was waiting there for him to grasp onto was the most emotive threat to rally the Russian people behind him: “The low-hanging fruit of NATO expansion.” And he has dined out on it ever since, even though he knows that NATO has no plans to expand to include Ukraine.

This is Putin’s war. He’s a bad leader for Russia and its neighbours. But America and NATO are not just innocent bystanders in his evolution.