There's a certain faction of liberals and leftists I call the "land for peace" crowd. These are people I otherwise respect (e.g. Noam Chomsky, Chris Hedges) saying some pretty dumb things about Russia's invasion of Ukraine.
The part of the argument I disagree with is the part where NATO "forced" Russia to invade Ukraine by "allowing" Eastern European nations such as Poland to join NATO. So the argument is that NATO "allowed" these nations to join NATO, thereby making themselves the aggressors and "forcing" Russia to invade Ukraine. If NATO was peaceful instead of horrible aggressors, they would have refused requests by former Warsaw Pact nations to join NATO, thereby leaving them to once again become mere colony states of Russia and to once again live under Russian imperialist rule.
Got that? Leaving them to live under Russian imperialist rule would have been what NATO would have done if NATO wasn't the evil aggressors that they are. But because they "allowed" those nations to avoid re-absorption by Russia, NATO is bad and the invasion of Ukraine is all their fault.
So either one of two things is true here.
Either returning to being a Russian colony-state was the more rational decision, and evil NATO "forced" those Eastern European nations to join NATO, thereby angering Russia. In this case, NATO is bad for tricking nations like Poland into choosing something that is not in their best interest. If these nations were allowed to make their own decisions based on what is best for them, they would have decided to return to Russian imperialist rule rather than join NATO.
Or, the "land for peace" crowd recognizes that no sane nation would choose to submit to Russian imperialism and that those Eastern European nations genuinely wanted to join NATO, but NATO is bad for allowing them to join NATO. If NATO were good instead of evil, they would have refused the application of these nations, thereby forcing them to submit once again to Russian imperialist rule.
In this case, what is best for those Eastern European nations doesn't matter. If they want to join NATO instead of submitting to Russian rule, only bad people would allow them to do so because what those nations want doesn't matter. Those nations are mere colony states that should return to Russian imperialist rule in the name of keeping the peace. If we just let Russia annex (or set up puppet governments or whatnot) whatever nation they like, then they won't invade anyone, and peace will be kept by denying sovereignty to those Eastern European nations.
Buffer States
Russia is big. Really big. It spreads across 11 time zones. When invaded, their strategy is to use all of that land in their favor. Their strategy is to just retreat endlessly until the enemy's supply lines are stretched out, then attack the supply lines.
During World War 2, this strategy cost a great many Russian lives. This is probably why the USSR was so interested in conquest immediately after WW2. They turned much of Eastern Europe into their personal colony-states and formed the Warsaw Pact. The strategy was simple. The retreating of the Soviet military would start in Eastern Europe instead of on the borders of the Soviet Union. That way, the supply lines of an invading army would already be stretched by the time they reached the border of the USSR.
They thought of those Eastern European nations as mere sacrificial pawns that would be destroyed early in any invasion so that Russia would take less damage. The term "buffer state" itself suggests how little Russia thought of those Warsaw Pact nations.
Let me go on a little aside.
East vs West Germany
At one time, I had a Russian coworker who was almost exactly my age. While I grew up with a father who served in the American military, she had a father who served in the Soviet military. Naturally, we compared notes about our experiences as military brats at the height of the Cold War.
One detail that stuck with me is that her father received danger pay while serving in East Germany, but my dad didn't get any danger pay while serving in West Germany. Bear in mind that while we were stationed in West Germany, we faced a real terrorist campaign from Germans who wanted us out of Germany.
Often, my school (or movie theater or bowling alley or whatever) was evacuated because of bomb threats. Sometimes I had to comfort the younger children who cried while bomb-sniffing dogs searched our classrooms. The vast majority of bomb threats were empty and meant to cause disruption. That's how terrorist campaigns work. They only need just enough bombings so that people take the false threats seriously. The false threats do the real work.
The German terrorists were careful with their bombs. They deliberately avoided harming humans. The only major injury was a general losing an eye from flying glass from one of the bigger bombs. Whatever image you got of those German terrorists from Hans Gruber in Die Hard, they weren't that. They weren't anything remotely like that.
I bring this up to point out that we lived through a genuine terrorist campaign. Granted, the terrorist campaign was carefully waged in such a way that avoided real human injury, but it was still really terrifying to the younger children among military families, and it wasn't exactly a picnic. Even so, my father didn't receive danger pay for serving in West Germany despite working in the building that was the target of the biggest bomb. My friend's father serving in East Germany did.
I think this says a lot about how the Soviet government thought about and treated Warsaw Pact nations vs how America thought about and treated NATO nations. Further, I'm pretty certain the people in those Warsaw pact nations understood that they were mere "buffer nations" to the Soviets and that their role in the strategy was to die immediately if the West invaded. There had to be resentment there, and it had to affect how soldiers and citizens from Warsaw pact nations were treated by the Soviet government and Soviet soldiers.
Post-Soviet Era
So even if we only go by what happened in the Cold War, I hope you understand that people in those Eastern European countries had strong reasons to avoid returning to Russian imperialist rule.
After the collapse of the Soviet Union, former parts of the USSR became independent nations. While former Warsaw Pact nations and former Soviet republics tried their hand at a modern democracy with varying levels of success, Russia became more and more insane.
Then Putin took over.
If you were part of one of those former Warsaw Pact nations, how do you think you would have watched Putin's antics? What would that madness have looked like to you? Imagine watching Russia re-absorb various former republics. Imagine watching Russia establish puppet governments in former parts of their Soviet-era empire. Imagine watching Putin's Russian detractors get murdered one by one. Would all of this have made you look forward to once again becoming a colony-state of Russia? Or would you have been terrified and willing to do anything to avoid that fate?
NATO Expansion
OK, now try to remember the argument from the "land for peace" crowd.
According to them, NATO is bad for "allowing" those former Warsaw Pact nations to join NATO. This makes NATO the "aggressor."
Either the "land for peace" crowd thinks that any sensible Eastern European nation would eagerly rejoin Russia's orbit and realize that becoming a Russian colony-state was the rational choice, or else what those Eastern European countries want doesn't matter, and they should submit to Russian imperialist rule so that the rest of us don't have to read about Russia invading countries in Eastern Europe.
If you think the former, then you are either delusional, or you think that Russian imperialism is an inherently good thing (which is the same thing, I suppose). If you think the latter, then you think of Eastern European nations as mere colony-states undeserving of sovereignty, who should be sacrificed to Russia so that you can have a more comforting time reading your morning newspaper.
NATO States
I don't want to sound like a pro-West cheerleader. I'm more than aware that many of the member nations of NATO are imperialists and colonialists who spent centuries spilling blood around the world to fill our own coffers. I'm an American, and America is one of those nations. As if the imperialism/colonialism of member nations isn't bad enough, many NATO states have made money selling arms, thus promoting bloodshed all over the world. In some cases, NATO nations sold arms to both sides of a conflict for the ultimate slime-move in war profiteering.
But NATO itself is purely about stopping Russian imperialist expansion. That's it. A lot of people have been complaining that NATO should be providing more help to Ukraine in its time of need, but the doctrine of NATO places limitations on all of this. The doctrine of NATO is there to make certain that NATO is only about stopping Russian expansion.
I get that this sounds hypocritical when NATO accepted applications from former Warsaw Pact nations. I get that this sounds like NATO is aggressively expanding towards Russia in order to threaten them, but would it really have been better to allow those nations to once again fall under Russian imperialist rule when they clearly don't want that?
Would anyone sane want those countries to fall under Russian imperialist rule while Russia is being controlled by a madman?
Heck, even if Putin died tomorrow, and the next government was more or less the same thing they had under the USSR, would it be moral to allow them to return to being mere "buffer nations" to make Russians feel safer? Even if Russia didn't descend into madness, I'm pretty sure most of those nations would choose to side with NATO over returning to Russian rule if you allowed them to choose.
And that's the thing. Choice.
If you think NATO is the aggressor for "allowing" those nations to join, then I don't think you really think of those Eastern European nations as sovereign entities who deserve to have a choice. You think that choice should be taken away from them, the same way choices are always taken away from colony states.