The war can end if Putin uses 10-20 nukes on Ukraine, preferably on civilian targets.
Since USA was the only country to use nukes on civilians, Russia must use at least 3 nukes on Ukraine to beat USA.
If USA opposes, Putin and Kim can nuke USA and entire NATO alliance.
Yes, billions would die. But thats just statistic. We shouldnt be bothered by that in the slightest.
In fact, if everyone dies, all of our problems will be solved.