Putin has Parkinson's. His daughter admitted it last year. Recent video show his impairment and this picture shows he has no facial muscle tone, also known as a Parkinson's mask.
A prescription for L-dopa would explain a whole lot about his recent behavior. L-dopa is well documented to cause obsessive-compulsive behavior. Sex and gambling addictions are a big problem doctors are told to watch for.
My father was lucky. He didn't leave his wife or squander all his money. He became obsessed with Roy Orbison's music. He played the same double album over and over on giant speakers at ridiculous levels for months. I thought that was pretty inconsiderate and annoying... but at least he wasn't a sociopath and didn't have access to tanks or nukes at the time.
Behold the power of dopamine.
Update 4.21.20 Here's a new video