Just because Putin feels justified in his actions doesn't make them right. The German nation (well the greater part of it) felt Hitler justified in his actions, the justification being the Versailles Treaty for the most part. That support only really faltered when his success did.
I think that much the same goes for Putin. He is a chancer like Hitler, and will only come a cropper when he takes one chance too many. We have a vested interest in seeing that happen sooner rather than later.
BTW, how many p's are there in appeasement again?