It's entirely too convenient of a plot device to use, but they could always pull the AT&T (Armored Tyranny and Terror) sphere out of mothballs. Planet sized machine god, meet moon sized planet destroying super-weapon. Of course, you have to wonder if any of the usual suspects have been tinkering with it in the intervening twenty plus years just for the hell of it. Imagine the size of the Reflex furnace you could install in it.