Here is great explanation by Reddit user 'Thegreasypole' on how the President - who is proving to be unhinged - has almost unchecked power to launch a legal nuclear strike:
>Legally the POTUS can order a strike. But without cause? Out of the literal blue?
Yes and No.
Some orders would be illegal orders. "Nuke Seattle, because my mother-in-law lives there and she is a colossal pain in the ass" would be an illegal order, for example. They can legally refuse those.
However, there are some circumstances where there is no doubt it definitely *would* be a *legal* order. Say, ordering a nuclear strike against a nation where congress has authorised use of military force or otherwise declared war. They cannot legally refuse those.
There is no doubt that(say) during the Iraq war an order to nuke Baghdad would have been a legal order.
This is problematic, because America never signed a peace treaty with North Korea, only an armistice. A temporary "truce" that does not end the state of war.
The US President still has outstanding congressional authority for any military act against North Korea from back in the Korean War.
An order to "Nuke Pyongyang, because they're developing nukes and we've got to snuff them out before they can develop a capability to first strike the US" is by any possible measure a legal order given the outstanding congressional authorisation of force.
So, yeah. He can order a launch against North Korea tomorrow, and legally everyone in the chain of command is required to execute it. For them not to do so would require them to break the law to save millions of lives. Something they *may* do, but which you couldn't reasonably rely on. Anyone doing so would likely face Treason, Dereliction of Duty and Failure to Follow a Legal Order charges and would have to rely on a pardon by Trumps successor.
>How would it play out if the POTUS decided to nuke Mecca and/or Medina? For whatever credible or incredible reason.
Here the military could hide behind the legal protection that congress hasn't authorised military force against Saudi Arabia and they are counted as a US ally. Here they'd have a decent legal defence in saying that they believed order was illegal, and you could reasonably expect them to exercise their right to refuse illegal orders whilst they desperately try and get Pence on the phone and beg him to trigger the 25th Amendment as the President has clearly lost his marbles.
Once Pence triggers it, with the ratification of 1/2 of the cabinet, they're off the hook as Trump is (at least temporarily) no longer President. Unless it turns out Pence is off his rocker too :)
>How would that play out in terms of a sub launching a nuke or 3 to destroy their target?
The president gives the order to launch to the military officer with "The Football".
The order is passed through to Central Nuclear Command (a room with a dozen flag officers in it) by this officer.
They get a chance to talk the president out of it.
If he insists... They give him pre-selected "launch plans" and he selects one (e.g. Full Out Attack on Russia.... OR... Limited Strike on North Korean Military Targets etc etc).
When he selects one they ask him to read "The Biscuit"... a small tablet of codes he has round his neck at all times. Every day he gets a new biscuit. That biscuit has 10 codes on it. Only 1 is the valid code for that day, so each morning he is briefed "Today, Mr President it is the 4th code from the top" for example.
If he reads the correct code, then legally the senior officer at nuclear command has to ring the launch centre and authorise them to launch. (if he gets the wrong code from the biscuit, they're off the hook. They assume he is a spy/assassin who has gained access to the biscuit and hang up on him and get a chance to call Pence).
If at this point the senior officer refuses to launch he is relieved of command and the 2nd officer in line has to do it. If he refuses, they keep moving down the chain of command with resignations until someone does it. Everyone who resigns is legitimately subject to Treason/Dereliction/Failure to Follow Orders charges.
At some point one agrees to do it and rings the nuclear launch centre, and gives them the code for the designated "launch option".
FROM THIS POINT FORWARD it is irreversible. The people further down the line do not know whether or not this is a drill. They are given the order to do this extremely frequently (in drills) and any refusal to do their jobs during even 1 such drill would see them permanently removed from their posts. The drills are done in such a way as they are *identical* to a genuine launch order. So, to them, this looks like the drill they've already done 100 times in their career except THIS time (unbeknownst to them) when they push the buttons they are live and missiles go *Whoooooooosh*, probably much to their shock and surprise.
About 30 minutes later (if the launch if from the US mainland) or about 10 minutes later (if the launch is from a sub stationed in the Northern Pacific) Pyongyang ceases to exist. The missiles cannot be aborted or diverted in flight, either.
The whole process is designed to be completed in less than 5 minutes, given it's plausible that the president may only have approximately that amount of time between being notified of an incoming strike and needing to launch... in order to ensure the US missiles are outside the blast radius of the enemy nukes by the time those enemy missiles hit their targets.
At any point (certainly with N Korea) Trump can do all of the above within 5 minutes of deciding to do so.
This train has no (legal) brakes. It was designed that way in the cold war. Your only protection is military officers deciding to go against their oath, their training, their procedures, the law and a lifetime of practice and risk legitimate conviction for Treason and a death sentence for doing so.... and about a dozen of them serially making the same decision.
>I'm hoping somewhere in this system of checks and balances, the launch fails long enough that someone else with more authorities intervenes....
There are NO checks and balances in a nuclear launch. NONE. It is specifically designed without such checks/balances based on two assumptions a) The President may have only 5 minutes to launch and b) America would never elect a lunatic.
The check and balance to this was meant to be the election. Thats it.