There is no peace with Russia because Russia can't tolerate Ukraine choosing its own destiny. The West could stop supporting Ukraine and let Russia eventually crush it, turn it into rubble, allow Russia to control all of its resources and turn those Ukrainians who manage to physically survive into cannon fodder in its next wars following intense Russification. That wouldn't be the end of Russia's push outwards and to the west as well in an effort to gain control over all of Eastern Europe. It's not in the security interests of the West to roll over and give up half of Europe just like that. Eastern Europe, including Poland, Czechia, Slovakia, Hungary, the Baltics and the rest, is part of Western civilization.
As for appeals to the realist school of international relations I have this to say: what Russia wants is incompatible with the size and sophistication of its economy. Russia is slowly bleeding to death while banging its head against a wall. When it runs out of resources to continue its campaign, there will be economic and political instability in Russia just like in the 1990s. There will be no WW III under that scenario, just another time of troubles in Russia. But there likely would be if it were to be allowed to freely rebuild and reconstitute its economy and its military.