Europe

Or when USA decides no more free war machines.

Thing is, from the US's standpoint this is, to put it coldly, a great cost-benefit ratio. The cost to the US has been chump change, with much of the transferred equipment nearing end of life anyway. Meanwhile, European allies are fiercely determined to make this very painful for Russia so there isn't a repeat performance.

I also wouldn’t call Russia’s actions imperialist as everything going on in eastern Europe the Russian response to NATO expansion.

If you buy the narrative about NATO expansion being equivalent to imperialism, sure. Or you could see it as a bunch of countries being afraid of Russia, so they joined NATO to gain protection. The narrative that NATO is going to attack Russia is simply wrong. It never has attacked Russia, and even with sending weapons to Ukraine it is supplying a nation purely with weapons against a foreign invader. Russia citizens could be immune from NATO supplied weapons tomorrow if Russia stopped the invasion.