I agree he may be suffering from early stages of dementia. I don't want to make light of it but I don't think that is the major explanation for his actions and words. NPD has been the primary animus for most if not all of his words and actions. This personality disorder may be adversely influenced by dementia and in fact it may exacerbate his NPD because of associated symptoms of paranoia and delusions not associated with NPD. Already he threatens his real political enemies. but I can not imagine what he would do if he is threatened by imaginary enemies or sees imaginary threats from foreign powers.
ignorance is the enemy
without equality there is no liberty