Putin's allies are active all over the world. This is literally his last hurrah, it's his ass on the line. He'll do anything that might help him turn this around and actually survive the next few years. His literal life very likely hangs on the outcome of the war, and like most people, I think he likes being alive.

Dude was literally contemplating nukes, before papa Xi told him it was a no-no. Probably still thinking about it, even though it'd just be a step closer to his suicide.