realistically speaking, this destroys NATO
There is a pretty good argument here for at a minimum reforming NATO. Some major points include that the US appears to be bluffing about having useful support to offer Eastern Europe through the NATO structure, also appears to have different defence priorities than Europe does, NATO itself failed to preserve peace and Europe looks like it has militarily atrophied to a pretty significant extent under NATO.
It is not clear how the situation will ultimately be interpreted, but the US's involvement here is pushing Europe towards being the next middle east. That isn't a great outcome.
Also, WW2 happened despite the Empire, and the UK wasn't really in a good place to fight it when they did — as in "we don't have enough guns and uniforms for everyone" not ready, despite having ended the military cutbacks 5 years before the war: https://en.wikipedia.org/wiki/British_rearmament_before_Worl..., https://en.wikipedia.org/wiki/Birmingham_Small_Arms_Company#..., https://www.iwm.org.uk/history/8-facts-about-clothes-rationi...
We don't have much choice really. Western Europe + Turkey are not going to put up with Russia rolling into Western Europe or Turkey. We have nukes and more money, people and kit than Russia.
Please tell me what would happen if Putin states "Job well done in Ukraine, all Nazi's are killed", and then withdraws his troops. NATO is going to invade Russia?