"We must vigorously support diplomatic efforts to deescalate this crisis and reaffirm Ukrainian independence and sovereignty. And we must make clear that Putin and his gang of oligarchs will face major consequences should he continue down the current path."

So we will deescalate by threatening to escalate? Sure, could work...

It could also mean he wishes to look impartial while calling for war.

You know, in looking over the wiki page for Bernie, I see the word 'diplomacy' twice, but not the word 'diplomat' even once. Because he ain't one, he's an activist. Which usually doesn't bode well for diplomacy.