Alas you don't have the mental capacity to apply the same understanding to Pakistan. You expect Pakistani PM to be all powerful (especially when it comes to military matters) but when it comes to USA a powerful and SANE president is not a requirement. It's alright for CIA to assassinate a non-complying US President but hey these are functional checks and balances!The US Presidency is only one post in a system with functional checks and balances at every level, and within the processes defined in the Constitution. Hence, USA is what it is despite its Presidents, and not because of them.
But that concept is probably beyond you understanding, as your malicious desperation shows. I will leave you to wallow in your own ignorance.