I mean the lack of sanctions, hasn't stopped Russia after taking Crimea, so it's only fair to assume Ukraine wouldn't be the end to Russia's (Putin's) expansion either. They implied so many times. Their enormous investments in the destabilization of foreign politics, have made it a very real possibility that the U.S. might drop out of NATO, if Trump gets reelected. Orban and Erdogan are also wild cards.
Such a development would put Estonia, Latvia, Lithuania, Moldova, and Poland at risk.
In long, that isn't insanity at all.