You should read more about what happened in 2014. the West (US) essentially overthrew the Ukraine government and installed their own. Ukraine bombed their own people in areas nearest Russia.
This was about NATO expansion and broken promises by the West.
As far as the armchair battle strategy, good luck with that. You would have had massive escalation and Russia wouldn't have just rolled over. The thought that we can easily take out Russia or defeat them without consequences by throwing some US air assets into the mix in Ukraine is fantasy. Where were the EU planes...???
Stick to your appeasement theory, history won't see it that way. For now, we (the US) just need to be out. The EU will handle it from here. I'm sure they'll just stick some air assets up, 10-20,000 troops, fire a few fancy missiles and it'll all be over.
The bigger fun will come watching the EU try to actually manage that corrupt piece of land going forward even if they get all of the former Ukraine land back and Russia pulls out tomorrow. (it wont) .You'll be babysitting that piece of dirt for a very long time while the military contractors get rich and your government keeps you focused on that while they rape your country and import another 10 million Muslims