His decision probably saved more lives than it took, especially with the Soviets bearing down on northern Japanese territory.
This is the part everyone forgets that added extra urgency to the decision. The Soviets had already seized all of eastern Europe and made no signs to withdrawal, and now that the war in the Pacific was at end-game they suddenly started massing troops to pretend they were part of the Pacific war all along so they could steal some more territory by partitioning Japan.
“His decision probably saved more lives than it took, especially with the Soviets bearing down on northern Japanese territory.”
Also, Curtis Lemay. He was ready to bring the B-17s, B-24s, & Lancaster bombers from Europe to join with the B-29s and burn every bit of Japan to the ground.