What would we do if NK or Iran tells us that a nuclear weapon has been smuggled into a large American city, and that we must meet their list of demands?
Imagine the public reaction if the president refused to negotiate.
Or, if they claim to have two smuggled in and actually light one off. At that point it wouldn’t matter much if they even had the second one.
This would all be a lot easier to take if had a real president.
Firstly, the “public” will never know. Secondly, and because of the first point, they will have to light off two nukes in two cities before gaining an earpiece to their demands. Yet, the gaining of an ear almost certainly tips off the return address.