Not only is this orders of magnitude more impactful than the other conflicts, but perhaps even more concerning is what in the world the endgame might be? By effectively throwing its entire influence into this war, the US has now effectively staked that influence on the outcome of the war. And it's the exact same situation for Russia. The two most nuclear armed nations are now in a conflict that is a must-win for both of them.
IMO this conflict ending up going nuclear is still highly improbable, but highly improbable is far closer to nuclear war than we've ever been.