So, now it’s late Summer, 1945, and the Japanese Empire is on its last legs. The Navy has been destroyed, the Army is mostly trapped in China and Burma, their merchant marine has been sunk. The American B-29’s have been fire-bombing almost every city in the country, against almost no resistance from the Japanese Air Force. The time had come to invade the Home Islands.
Invasion was a costly alternative, but we didn’t have any particular reason to believe other options were workable. A blockade might starve them out, but there was no assurance of that. Besides, the result would be to have the Japanese grudgingly admit that they’d lost, to bargain for a less than unconditional surrender, and to leave future generations open to a “stabbed in the back” theory, like Germany after WWI. An invasion was the only way to convince the Japanese that they really had lost the war.
The cost was going to be horrific, on both sides. We estimated there’d be a million Allied casualties, and upwards of five million Japanese casualties. Japanese plans were to defend the Home Islands the way they did Okinawa and Iwo Jima — a defense in depth by soldiers who would have to be dug out and killed one by one. What we didn’t know was the extent to which the civilian population would be involved. Males were inducted into home defense units. Women and school children were shown how to tie a knife to a broomstick and attack allied infantry. Another thing that we didn’t know was Japanese preparations for kamikaze operations.
At the start of the US bombing campaign, the Japanese high command had decided to hide their remaining aircraft in protected shelters and rail tunnels, and to reserve enough aviation gasoline to fly 6000 one-way sorties. What Curtis LeMay thought of as a weakness that allowed him to bomb from low altitude was actually an iron determination to strike as hard a blow at the invasion fleet as possible. And it would be a hard blow. Although we looked on the kamikaze pilots as fanatics, they were actually patriots, doing their final duty. Using kamikaze tactics during the battles for Iwo Jima and Okinawa, the Japanese put more US ships out of the war, with fewer losses to themselves, per ship sunk or damaged, than they did with any of their more conventional campaigns.
In addition, southern Japan does not have that much coastland and hinterland suitable for an amphibious invasion. The Japanese High Command predicted almost exactly when and where we would invade, and had distributed their forces accordingly — an initial foothold on Kyushu Island, followed by an invasion of Honshu, with landings on either side of Tokyo Bay. Much of the land behind the beaches is shown as agricultural (rice paddies), but that doesn’t mean it is level. The paddies are enclosed in dikes, and in many cases are stepped in terraces. From a tactical standpoint, this means that tanks crossing the dikes and terraces will have their vulnerable undersides exposed to the defenders.
But, we had The Bomb. We had choices on how to use it, but little assurance that anything short of destroying a city would convince the holdouts in the Japanese military and government. Using it would be horrific (I know, that’s the third time I’ve used that phrase), but consider that we had already destroyed a greater area of the three largest cities in Japan than we did in all of the cities of Germany. The only difference here would be that we were doing it with one bomb in one instant, rather than waves of bombers over several days. It was a terrible weapon, and we had to demonstrate to the world what a terrible weapon it was. Even then, it still took over a week, and a second bomb, for the Japanese government to actually admit to defeat. They signed the articles of surrender seventy years ago today.
In The Prisoner and the Bomb, Laurens van der Post, an Afrikaner officer imprisoned in Indonesia, said that the prison camp guards seemed to be working themselves up to something at the end of July and the beginning of August. The prisoners believed there was going to be a massacre. But after the bombs had dropped, the guards attitude changed, becoming almost resigned. The use of the atomic bomb, and the way it was used, finally convinced even the most fanatical holdouts that Japan had been well and truly defeated. And it convinced the world that we had to do something to limit their use.