The whole WW3 scare is silly. Putin isn't interested in a 1000 year reich. He's a KGB spy who spent his life resisting western influence, he is doing what he does best. Now that they have him feel cornerned though, things will get very bad. He may invade all the former soviet sattelites and the west should stay out of it unless WW3 is on the calendar.
Where do you draw the line? I don’t think any of those are acceptable. If you don’t fight a expansionist tyrant then what do you envision happens? Sacrificing innocent free countries to (maybe) appease a monster is completely out of the question.
Things can get bad if you interfere - things are guaranteed to get bad if you don’t
Tell that the Iraqis or Libyans or Syrians or Afghanis. Oh wait, they are terrorists when they do it but Ukrainians are freedom fighters?