Eastern Europe was screaming about how dangerous this was, but they weren't listened to.
One of the most insane things is how after Russia's surprisingly poor military performance in the Georgian war, the Merkel government was disturbed not that Russia invaded Georgia, but at the level of disarray in the Russian army, and sought a deliberate policy of improving the Russian military. They perceived Russia as a bulkwark against e.g. Islamic extremism, and as a potential strategic partner. They supported for example Rheinmetal building a modern training facility in Russia and sent trainers to work with the Russian military.
With Georgia I could understand (though adamantly disagreed) how some dismissed it as a "local conflict" because it could be spun as "Georgia attacking an innocent separatist state and Russia just keeping their alliances". But after 2014 there was no viable spin that could disguise Russia's imperial project. Yet so many kept sticking their fingers in their years going, "LA LA LA, I CAN'T HEAR YOU!" and pretending like we could keep living as we were before. It was delusional and maddening.
The EU has three times Russia's population and an order of magnitude larger of an economy. In any normal world, Russia should be terrified of angering Europe, not the other way around. But our petty differences, our shortsightedness, our adamant refusal to believe deterrence is needed, much less to pay to actually deter or even understand what that means... we set ourselves up for this.
And I say this to in no way excuse the US's behavior. The US was doing the same thing as us (distance just rendered Russia less of a US trading partner) and every single president wanted to do a "reset" of relations with Russia, which Russia repeatedly used to weaken western defenses in Europe. And it's one thing for the US to say to Europe "You need to pay more for defense" (which is unarguable), even to set realistic deadlines for getting defense spending up, but it's an entirely different thing to just come in and abandon an ally right in the middle of their deepest security crisis since World War II. It's hard to describe to Americans how betrayed most Europeans feel at America right now. The US organized and built the world order it desired (even the formation of the EU was strongly promoted by the US), and then just ripped it out from under our feet when it we're under attack.
A friend once described Europe in the past decades as having been "a kept woman" to America. And indeed, life can be comfortable as a kept woman, and both sides can benefit. America built bases all over Europe to project global power; got access to European militaries for their endeavours, got reliable European military supply chains, etc and yet remained firmly in control of NATO policy; maintained itself as the world's reserve currency; were in a position that Europe could never stop them from doing things Europeans disliked (for example, from invading Iraq); and on and on - while Europe decided that letting the US dominate was worth being able to focus on ourselves. But a kept woman has no real freedom, no real security, and your entire life can come crashing down if you cross them or they no longer want you.
