I think counting on a coconspirator to become rational and brave is a hope. He's president for life though and lives in a literal villain lair. Miles of impassible mountains with one way in on one said, patrolled by heat seaking drones and all matter of radio and seismic sensors, and an frigid ocean patrolled by everything up to nuclear submarines on the other. I'd put about as much faith in it as I would waiting around for natural causes or a jilted lover, a disgruntled chef, or whatever dumb luck might bring the world closer to peace.

To add to this, I think Russia has already committed to losing at least ten million people if hot war breaks out, and for Putin that would be like no big deal if it got him a good enough strategic advantage, whether it's pushing back NATO or undermining democracy. That is to say, I hope it won't take an utter humanitarian catastrophe to rock Putin's goons hard enough to turn on him.