Could the POTUS implement some form of checks and balances with regards to his otherwise unilateral, unquestionable ability to use nukes? Without needing congress to pass a bill?
If so, would he HAVE to use an executive order? Or, could he just tell those lower then him in the chain of command to ignore him if some condition is not met, or if someone like the VP didn't agree with the choice? Or could he even bestow upon the VP or others the ability to veto his decision?