Yes, if Biden decided to invade Canada for no good reason, I imagine a lot of patriotic Americans would wisely refuse to fight.
The Causes and Consequences of the Ukraine Crisis
Russians are fighting to preserve their country from the same evil that has enslaved us. We should be cheering them on, and calling for Ukrainians to join them rather than serving as cannon fodder for a far greater evil than anything that ever came out of Russia (and that's saying something.)