Every August, you start seeing essays from professional and amateur journalists on the usage of the atomic bombs to end WWII. This month marks the 75th anniversary of that occasion, so you know there are going to be plenty more. And if this year is like all others, some of those essays will contain (or will have comments that contain) much wailing and gnashing of teeth about how we didn’t have to drop the bombs.

At least some of their reasoning involves post facto arguments, in that they use information that wasn’t available at the time. Or they rehash old, tired arguments that have been acknowledged and dismissed with justification.

What if we went back to the summer of 1945, and looked at the matter using only that information which was available at the time?

First, let’s set the stage – and add some information that is very often overlooked.

President Truman was very new at the job. He had only taken over the presidency in late April on the death of Franklin Roosevelt. And, he’d only been vice-president since January, a job that was so insignificant at the time that he hadn’t even been briefed on the existence of the Manhattan Project.

Naturally, when informed of the program, he needed to get up to speed on it right away – and the options for using the bomb. He created a committee of military leaders, political figures, scientists, and civilian business executives to consider all his options and make a recommendation. This “Interim Committee” of about twenty people quickly set to work. On June 1, they reported back with the recommendation that the bomb should be used as soon as possible, against a military-industrial target, and without prior warning. Every alternative that people thought of – and think of – had been considered – and dismissed.

The arguments for dismissing those alternatives haven’t changed. A demonstration or test could be accused of being faked, and there was no guarantee that the bomb would work. Yes, every step of the process had been studied and tested, but until the Trinity test in June, no one knew if the bomb would actually work – or what would happen if it did. Even with the results of the test in hand, there was still room for doubt. An explosion under controlled conditions is a heck of a lot different from dropping a bomb.

As far as invading Japan, geography dictated that there was only one area on Kyushu that could be used for the initial assault. We knew it, and Japan knew it, too. We couldn’t confuse them by hinting at alternative landing sites, like we did with the Germans for D-Day. Given how intense the fighting was on Okinawa in the spring of 1945, any fighting on the Home Islands would have been a bloodbath. ULTRA intercepts in early August showed that Japan was moving so many more troops into the invasion areas that Navy leadership was having serious second thoughts about it. And even if a fraction of the civilians were following the same “fight, and if you can’t fight, kill yourself” orders that had been given on Okinawa, over half a million civilians could have died. The Japanese really did not know to surrender. In their 2,600 year history, they had never been subjugated by an outside power; and in the entire course of the Pacific War, not a single Japanese unit of even the smallest size surrendered. Individuals did give themselves up, to be sure, but only after they were completely surrounded, out of weaponry, or physically unable to fight.

What about the “blockade and bomb” option, where the Allies would set up a naval blockade of the Home Islands and continue to use conventional bombing of military and industrial targets? Aside from the problem that it would extend the war for at least several months (with everything that would entail), by that stage of the war, almost all the worthwhile targets had been hit. What was left on the list were rail yards, bridges, and harbor facilities – the keys to Japan’s transportation network. With the majority of Japan’s food being produced on the northern island of Hokkaido and the majority of the population on southern Honshu, trashing the food distribution network would have led to massive starvation. This is often overlooked by the “anti-bomb” group.

Another thing that gets overlooked is that if you want an enemy to surrender, you need that order to come from someone with the authority to make it stick. In the case of Japan, that was the Emperor. He was the person we had to persuade; he was the one we had to convince that resistance was futile. While technically the country was a constitutional monarchy, in practice it was a military “dictatorship by committee” during the war. The military men running the show weren’t going to yield. Something big and dramatic was needed to get the attention of the Emperor.

Also, we weren’t the only nation involved. Although we did have the most forces involved in the Pacific Theater, Great Britain, Australia, China, and India were among those who had forces involved, and the Soviet Union was one of the “Big Three” who convened at Potsdam that spring to decide the fate of Japan. Any decisions involving Japan’s surrender would have to have their input at the very least.

Speaking of the Soviet Union, the alliance of convenience with them against Nazi Germany was coming apart. If the war against Japan were to go on much longer, it would be impossible to keep them away from the peace settlement. Here, we’re getting into the realm of speculation (which I don’t want to do in this case), but it’s worth considering. If the war dragged on, the eventual peace would create something like what existed in Europe. Picture the Soviets controlling all of Korea (not just the north) and a divided Japan – perhaps with Hokkaido under Soviet control (the Kuril Islands, the chain stretching from Hokkaido to Kamchatka, are already divided and disputed). A Cold War in the Far East as well as in Europe…

Back to reality…..

At the very least, a quick end to the war would strengthen the US’ position over the Soviet Union in the post-war world. It’s been said that the bombs were the last shots of WWII – and the first shots of the Cold War. Whatever you think of that, it’s hard to deny that there were post-war considerations involved in the decision to use the bomb(s).

What the evidence does indicate is that the view of the bomb as a potential way to end the war quickly–in the hope of (1) avoiding the need for an invasion with resulting casualties that by any standard would be of intimidating proportions, (2) minimizing the USSR’s postwar leverage, and (3) not having to confront debate over concessions on the terms of unconditional surrender–was the driving force in the minds of the US leadership team before Potsdam, and before the acquisition of intelligence showing much-larger-than-expected Japanese forces on Kyushu. Nonetheless, it is certainly plausible that the buildup disclosed by early August reinforced the belief that the decision to use the bomb was the path of least resistance.

Meachin, Douglas J., The Final Months of the War With Japan: Signals Intelligence, U.S. Invasion Planning, and the A-Bomb Decision, Center for the Study of Intelligence, CSI 98-10001, December, 1998.
https://www.cia.gov/library/center-for-the-study-of-intelligence/csi-publications/books-and-monographs/the-final-months-of-the-war-with-japan-signals-intelligence-u-s-invasion-planning-and-the-a-bomb-decision/csi9810001.html

Finally, on the home front, pressure was building to get the war over with as soon as possible. With Germany defeated, the campaigns were about turning the entire military might of the country against Japan.

Propaganda posters from 1945.

There would have been hell to pay in Congress if the war dragged on for months and it came out – and it would have – that the military had spent billions on a secret weapon that could have ended it in days. Do you really think the American public would have said “Oh, gee, that weapon was too awful! It’s a good thing we didn’t use it!”