Without a doubt we meddled in Ukrainian politics to push out a Russian puppet in favor of our own. If that's the "foolishness" DJT is referring to then he's also lost all sense of proportionality.
So say we stayed completely out of it: Would there have been a rebel uprising had a Russian puppet government remained? Would the airplane have been shot down? Would Crimea have been annexed? That's quite a bit history right there in that region.