“””””1. The Demonstration. Notifying the Japanese government that we have a new catastrophic weapon, and we will use the first one to destroy the fleet anchorage at Hashirajima - and do it quickly before any fleet units can disperse.”””””
It was World War II, the Japanese might want to shoot that plane down rather than decide to just watch to see if it really could wipe out the fleet at the harbor.
Without question. To counter that you put up 50 or so B-29s with at least 100 VLLR P-51s out of Iwo for high CAP and you cover the plane with the bomb until he gets to the Release Point.