For a sense of scale (only scale, money is definitely not the most important criteria), the EU currently spends twice as much on their military as Russia: https://en.wikipedia.org/wiki/List_of_countries_with_highest...
So if (when) American support disappears, I expect Russia to continue to not go anywhere fast while wasting a lot of lives in the process. I also expect this to surprise Putin, as he thinks Russia is a Great Power and therefore can only be stalling if Ukraine is supported by another Great Power and doesn't recognise that (1) Russia isn't, and (2) the EU kinda is, sort of, when it feels like acting with unity rather than as 27 different nations.
The sole reason Russia invaded Ukraine was that it was flirting too much with NATO.
Putin might be a lunatic, but he is not stupid.
Finland is a member.
Lithuania is a member.
The sad reality is that your logic is just a twisted pretzel to support the position you wish to take which is you support Russia's unprovoked invasion of Ukraine.
The US military industrial complex is a huge beast that needs an enemy to exist. There is so much money in the game.
Was it the one where the USA, along with the UK and Russia, all jointly signed an agreement to respect Ukraine's (and several other post-USSR nations') independence and sovereignty in their existing borders (as of 5 December 1994), including an obligation to seek immediate Security Council action to provide assistance to the signatory if they "should become a victim of an act of aggression or an object of a threat of aggression in which nuclear weapons are used", so that Ukraine would give up the nuclear weapons it had accidentally inherited from the USSR?
Put it another way: given your stance on the US mil-ind complex, do you think this war would stop if the USA completely vanished from the international scene?
Because the EU is right next door and also doesn't want Russia thinking it can do stuff like this.