Where you gonna get the pilots who'll drop the bombs on the American people? If I were the pilot and got the order to put a smart bomb in the local Piggly Wiggly full of my fellow Americans (civilians too), I'd head for the nearest govt building.... oops, wrong target.
If there were another "civil war" in America, why is it automatically assumed that the established govt being revolted against, and not the "rebels", would control all the "hardware"? Nothing could be further from the truth. The govt pilot in the F-22 would likely have a few "rebel" F-22s, or F-18s, or whatever a "rebel sympathiser" flies, right on his ass, shooting missiles and cannons at him. He'd be too busy trying to not get shot down to worry about hitting a ground target full of rebelious citizens. Don't think so? Were did Robert E. Lee, Jeb Stuart, Stonewall Jackson, Longstreet, Pickett, etc. get their military training? Was it the U.S. Army's West Point, or some rinky-dink military school set up by the confederate rebels after the war started? In 1861, Robert E. Lee was the best damn general in the U.S. Army, which just proves the point that likely at least half of today's military men & machines would go over to the "rebel" side.