Tirek has taken over Equestria. But Equestria has some powerful allies. Allies in the form of a squadron of US Air Force A-10 Warthogs, who don't take kindly to allied nations being invaded.
The Changelings have lost. Their cities destroyed, their Queen dead. Yet the war is not over. A bomber crew is assigned one final mission to remind the Equestrians of this fact: By using a Nuclear bomb to wipe the city of Las Pegasus off the map.