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.
He even made a speech at the Sportpalast in Berlin in which he stated that the Sudetenland was "the last territorial demand I have to make in Europe". So all's fine, and we don't have to worry about Germany.
After Reginald Drax's mission to Moscow failed, the Soviet Union ended up signing its famous non-aggression pact.
Italy was allied, Spain was neutral/aligned. Turkiye was neutral.
Poland could only count on UK and France[0].
Compare to now, where the NATO military bloc is massive. No one would dare risking a military confrontation in these circumstances.
If anything, when there are any tensions between two non-NATO countries, it makes it more urgent for one to oppose the other joining NATO (attacking before they'd join NATO would stave off them joining, attacking after they'd join NATO would lead to an unwinnable fight).
0: https://en.wikipedia.org/wiki/Anglo-Polish_military_alliance
So I wanted to show that people have also used cheap excuses like this in the past, and that we shouldn't give Russian propaganda the benefit of the doubt.
Of course there weren't any atrocities commited against the Sudetendeutsche population, I just assumed everyone knew that, but that's due to my German-centric view of history.
I should have expected this, as sarcasm doesn't translate well over text, especially if people don't share the same cultural background.