Non stealthy Tanker Fleet. The Achilles Heel of a moder Air Force. In WW2 the lightning advance to Germany from Normandy stalled due largely the inability to keep the vehicles gassed up. Same reason the German Counter Offensive died in the Ardennes. No fuel to keep the Panzers moving. Even in Ukraine the original invasion stalled because of lack of fuel and the Javelin. If something is carrying a lot of fuel, it's inherently ready to turn into a fireball.