Grave of the fireflies

(Source)

Some people object to the U.S. dropping the atomic bomb on Hiroshima and Nagasaki to end the war with Imperial Japan:

1. If the U.S. hadn't dropped the atomic bomb, then arguably the U.S. would have continued firebombing Japan. This evidently would have been much worse for Japan than the two atomic bombs. Victor Davis Hanson explains in The Second World Wars:

The March 9–10, 1945, napalm firebombing of Tokyo remains the most destructive single twenty-four-hour period in military history, an event made even more eerie because even the architects of the raid were initially not sure whether the new B-29 tactics would have much effect on a previously resistant Tokyo. The postwar United States Strategic Bombing Survey—a huge project consisting of more than three hundred volumes compiled by a thousand military and civilian analysts—summed up the lethality of the raid in clinical terms: "Probably more persons lost their lives by fire at Tokyo in a 6-hour period than at any time in the history of man." Over one hundred thousand civilians likely died (far more than the number who perished in Hamburg and Dresden combined). Perhaps an equal number were wounded or missing. Sixteen square miles of the city were reduced to ashes. My father, who flew on that mission, recalled that the smell of burning human flesh and wood was detectable by his departing bombing crew. A half century later, he still related that the fireball was visible for nearly fifty miles at ten thousand feet and shuddered at what his squadron had unleashed...

Both atomic bombs were dropped from B-29s, the only American bomber capable of carrying the ten-thousand-pound weapons and reaching the Japanese mainland from the Mariana bases. Most controversy over the use of the two bombs centers on the moral question of whether lives were saved by avoiding an invasion of the mainland. The recent Okinawa campaign cost the Americans about twelve thousand immediate dead ground, naval, and air troops, and many more of the fifty thousand wounded who later succumbed, with another two hundred thousand Japanese and Okinawans likely lost. But after the bloodbaths on Iwo Jima and Okinawa, those daunting casualties might well have seemed minor in comparison to the cost of an American invasion of the Japanese mainland.

The ethical issues were far more complex and frightening than even these tragic numbers suggest. With the conquest of Okinawa, LeMay now would have had sites for additional bases far closer to the mainland, at a time when thousands of B-17 and B-24 heavy bombers, along with B-25 and B-26 medium bombers, were idled and available after the end of the European war. Dozens of new B-29s were arriving monthly—nearly four thousand were to be built by war’s end. The British were eager to commit Lancaster heavy bombers of a so-called envisioned Tiger Force (which might even in scaled-down plans have encompassed 22 bomber squadrons of over 260 Lancasters). In sum, the Allies could have been able to muster in aggregate a frightening number of over five thousand multi-engine bombers to the air war against Japan. Such a force would have been able to launch daily raids from the Mariana Islands as well as even more frequently from additional and more proximate Okinawa bases against a Japan whose major cities were already more than 50 percent obliterated.

A critical consequence of dropping two atomic bombs on Hiroshima and Nagasaki may have been not just precluding a costly American invasion of Japan, but also ending a nightmarish incineration of Japanese civilization. Otherwise, by 1946 American and British Commonwealth medium and heavy bombers might have been able to mass in numbers of at least two to three thousand planes per raid. Just two or three such huge operations could have dropped more tons of TNT-equivalent explosives than the two atomic bombs. Within a month, such an Allied air force might easily have dropped destructive tonnage equivalent to ten atomic bombs, following the precedent of the 334-plane March 9–10 fire raid of Tokyo that killed more Japanese than either the Hiroshima or Nagasaki nightmares.

"It seemed to me," Japanese prime minister Kantaro Suzuki remarked after the war, "unavoidable that, in the long run, Japan would be almost destroyed by air attack, so that, merely on the basis of the B-29s alone, I was convinced that Japan should sue for peace. On top of the B-29 raids came the atomic bomb, which was just one additional reason for giving in...I myself, on the basis of the B-29 raids, felt that the cause was hopeless."

2. In addition, the historian Gerhard Weinberg writes the following in his paper "Some Myths of World War II":

The other myth in need of another look is the controversy over the anticipated American and Allied casualties in the two planned invasions of the home islands of Japan of which Truman authorized the first in mid-June 1945. Invariably the likely casualties of the Chinese, Russians, British, and others are omitted from this discussion. Similarly the planned Japanese killing of all the prisoners of war they held is ignored.

Perhaps into the discussion one should also enter the anticipated casualties on the Japanese side about which there was no controversy within the Japanese leadership. It was accepted that there would be 20 million such casualties. This figure those in charge in Tokyo unanimously deemed acceptable until the second atomic bomb suggested to some of them that the Americans could drop an indefinite number and hence not have to invade at all.

In this connection, it may be worth noting that both the British government and Stalin had agreed to the use of the atomic bomb before Washington had asked them.

Now that the focus has turned to Japan, this may be an appropriate point to touch on Japanese war aims. These are all too often described as limited to resource-rich parts of Southeast Asia. The Japanese certainly wanted them, but the inclusion of India, Alaska, New Zealand, and Cuba in Japanese planning—to mention merely a few—hardly points to a modest program of annexations. One cannot help wondering what Fidel Castro would think of the inclusion of Cuba in the Greater East Asia Co-Prosperity Sphere—and of being rescued from this prospect by the Yankees.