took 3, but about the president being checked for initiating it I have no idea.

but the president can single-handedly order an attack. Back toward the end of the Watergate scandal, when Nixon was starting to get a bit loopy and drinking a lot, Secretary of Defense Schlesinger told the Chairman of the Joint Chiefs not to follow any orders from Nixon that Schlesinger had not also approved - he was afraid Nixon would light off nukes in order to save his presidency, which he had the unrestricted power to do. http://www.thedailybeast.com/the-most-patriotic-act-of-treason-in-american-history

If they do have something in place to countermand or challenge such an order, it's under the radar and technically illegal.

and took steps to prevent him from annihilating the world. So I am pretty sure they have done the same thing with LOSER 45. He has no self control, is dumb & if he thinks the world is against him, (which they are)

not to follow orders from Nixon without checking with him first.

At least everyone knows now that he's often incoherent.