You left out the biggest difference, that of Americans being fiercely independent, which is vastly different than the populations of Europe and especially the old USSR.
The mis-judgement on the liberal’s part is that Americans always give anyone a BIG benefit of the doubt, until it becomes obvious that benefit is misplaced and there are indeed ulterior motives, then we're ready for a fight.
That is not true about the Baltic Republics, they were always fiercely independent. However, when a Communist-sympathizing president, FDR, hands over your countries to the Communists, after the Baltic people had already spent years fighting Hitler and Stalin, there's not much left.
I doubt that we will be able to fight the tanks here either, those who can have already fled, just like they did during and after WWII, and there are too many elderly and infirmed patriots now here. And too few of us in general. And we've had Communists in power for too long now.