He has mental/IQ issues.
Not the sharpest halberd in the castle. :)
Then he fell under the hypnotic sway of this (to him) irresistibly beautiful pathological narcissist (and mother figure). She obviously treats and commands him around like a puppy.
And this recent "blunder" is what you get. He is obviously desperate to demonstrate his manhood (of which he was deprived by being a royal and by his wife).
I don't say this to cut him slack or to excuse his behavior. It is what it is.
That said, someone in his family needs to get to him and try to open his eyes to the destructive effect his wife is having on him, his family, and his country.