If you fly at Mach 11 and the enemy at Mach 1.3, you fly at vastly different altitudes. You fly roughly at 80 km, and the enemy at 15 km height. The enemy has n

If you fly at Mach 11 and the enemy at Mach 1.3, you fly at vastly different altitudes. You fly roughly at 80 km, and the enemy at 15 km height. The enemy has nothing they can shoot at you. Whatever you decide to do, either you hit, or you miss, but you don't lose. Of course, you are still vulnerable to ground-based missiles, but in the context of an air battle, you have nothing to fear.