From Aubrey Turner, comes this interesting thought :

I wonder whether it might have a deterrent effect on certain Islamist elements if it were to be leaked that the US has an ICBM or three targeted at the coordinates 21°25’24” N, 39°49’24” E. If an American city were to be attacked with WMD (any type of NBC weapon), these coordinates would become quite warm about 15 minutes later.

I haven’t looked up that map reference, I would guess that it is Mecca.