How about this: "Suitcase nukes work."
Not at all. He need only lean back in his chair, sip his favourite beverage, and scroll through the possibilities offered to him, here, at his own website, and a couple of other on-line locales where similar discussions are under consideration.
Should they not offer him an easy answer, they'll at least provide samples for quick rejection, and maybe, some inspiration for a final choice.
But if I was Simmons, I'd have an answer for those who privately bug me for the answer, promising eternal secrecy should I confide. In fact, I'd have a different answer for each of them....
[You ever see the ending of the film version of H.G. Wells' The Time Machine? That'd be the 1960 George Pal version, starring Rod Taylor.]