Counterfactual history — or alternate history — is not a genre that most professional historians indulge in. We’re quick to sneer at it, for good reason: it’s pure fantasy, and about as relevant to history as Star Trek is to serious physics. (Star Wars is, unfortunately, another story.)

But sometimes the genre of What If? can be somewhat useful at pointing out assumptions in the current historical narrative. Controversial topics can cause us to get stuck in narrative ruts, parroting back the same sequence of events, taking for granted what did happen and losing sense of the contingency — the way in which things might have turned out otherwise.

In the comment section of a post on here from last week, Michael Krepon of the Stimson Center (and Arms Control Wonk) posted an interesting hypothetical question:

What do you think would have happened differently had Japan not surrendered and if the US kept using atomic weapons when they were ready? We know what would have been the same: Japan would have lost the war. We can readily imagine what would have been different in Japan: more smoldering, radioactive rubble. But what would have been different outside of Japan?

I strangely wonder about the question. I suspect that there would have been an open revolt at Los Alamos. Would Truman have said, “enough”? Would attitudes about the Bomb in the US & Russia have been any different? Attitudes toward the US?

It’s worth noting explicitly that this is a very different question to the “what if we hadn’t dropped the bomb at all?” question, which is more common and has some pretty well-worn narrative ruts (deaths of bomb vs. invasion, whether demonstration would have worked, the importance of the Soviets invading Manchuria vs. the bomb, etc.). This query presumes that Hiroshima and Nagasaki happened as they did, but instead of surrendering shortly thereafter, the Japanese had kept on going, and Truman had OK’d the dropping of more bombs.

I gave some gesture at a response, synthesizing some interesting work that I thought was relevant to the issue. I also managed to get Michael Gordin, author of Five Days in August: How World War II Became a Nuclear War, to chime in as well. You can read the responses at the post linked to above.

How realistic is the question? Pretty realistic, as it turns out. As Michael G. argued in his book, the notion that “two bombs were enough” wasn’t actually dominant at the time — some people thought it would be “enough,” but most people, naturally, had no idea how many would be “enough.” In early August 1945, nobody knew whether the atomic bombs would be the “war-ending weapons” that they were later (controversially) touted as being. Only after surrender do you really get into the idea that two are “enough,” if not too much.

This week’s document is one of the more vivid demonstrations of this fact. It is a transcript of a telephone conversation between General John E. Hull, who was involved in Allied planning in the Pacific theatre, and Colonel L.E. Seeman (here incorrectly noted as “Seaman”), an assistant of Groves, on August 13, 1945. The subject is the “third shot” — the next bomb ready for use after Nagasaki, which was anticipated to be ready by August 23 — and the shots beyond that.

From the transcript:

S[eaman]: … Then there will be another one the first part of September. Then there are three definite. There is a possibility of a fourth one In September, either the middle or the latter part .

. H[ull]: Now, how many in October?

S: Probably three in October.

H: That’s three definite, possibly four by the end of September; possibly three more by the end of October; making a total possibility of seven. That is the information I want.

S: So you can figure on three a month with a possibility of a fourth one. If you get the fourth one, you won’t get it next month. That is up to November.

H: The last one, which is a possibility for the end of October, could you count on that for use before the end of October?

S: You have a possibility of seven, with a good chance of using them prior to the 31st of October.

H: They come out approximately at the rate of three a month.

That’s a lot of bombs. (Incidentally, this also lets you estimate the maximum stockpile size throughout much of the late 1940s. In practice, bomb production fell off in the confusion at the end of the war, and didn’t pick up again until 1948 or so.)

H: That is the information I wanted. The problem now is whether or not, assuming the Japanese do not capitulate, continue on dropping them every time one is made and shipped out there or whether to hold them up as far as the dropping is concerned and then pour them all on in a reasonably short time. Not all in one day, but over a short period. And that also takes into consideration the target that we are after. In other words should we not concentrate on targets that will be of the greatest assistance to an invasion rather than industry, morale, psychology, etc.

And that also takes into consideration the target that we are after. In other words should we not concentrate on targets that will be of the greatest assistance to an invasion rather than industry, morale, psychology, etc. S: Nearer the tactical use rather than other use.

“The other use”: what a euphemism! Though perhaps no worse than “strategic bombing,” which is a nicer formulation than “terror bombing” (as it was, for awhile, originally called, in the context of firebombing). This idea of one-bomb-as-you-get-them or holding them up and then “pour[ing] them all on” is one of the ones that has stuck with me. A “rain of ruin” indeed. It’s tempting to imagine this as periods of peace punctuated by periods of terrible destruction, but it’s probably worth noting that there would have likely been firebombing during those “peaceful” periods as well, so there’d be a lot of terrible destruction to go around.

H: That is what it amounts to. What Is your own personal reaction to that?

S: I have studied that a good deal. Our own troops would have to be about six miles away I am not sure that the Air Forces could place it within 500 feet of the point we want. Of course, it is not that “pinpoint”. Then the stage of development has to be considered. The work it is liable to be used for the more or less has to be explosive effect. It would be just a gamble putting or sending those troops though.

H: Not the same day or anything like that. We might do it a couple or three days before. You plan to land on a certain beach. Behind which you know there is a good road communication and maybe a division or two of Japanese troops. Neutralization of that at some time from H Hour of the landing back earlier, maybe a day or two or three. I don’t anticipate that you would be dropping it as we do other type bombs that are in support of the infantry. I am thinking about neutralizing a division or a communication center or something so that it would facilitate the movement ashore of troops.

S: That is the preferable use at this time from that standpoint. The weapon we have is not a penetration weapon. The workmanship is not as good as possible. It is much better than average workmanship. We are still developing it though.

H: From this on more or less of the timing factor, how much time before the troops actually go into that area do you think would be the safety factor? Suppose you did get a dud or an incomplete explosion, what safety factor should you consider, one, two, three days?

Suppose you did get a dud or an incomplete explosion, what safety factor should you consider, one, two, three days? S: I think we are sending some people over to actually measure that factor. I think certainly by within 48 hours that could be done. Everything is going so fast. We would like to train people and get them in a combat spirit to do that. I think the people we have are the best qualified in that line. Of course, as you say, if it is used back in a kind of reserve line or in a reserve position or a concentration area but that you wouldn’t be up against right away.

I think certainly by within 48 hours that could be done. Everything is going so fast. We would like to train people and get them in a combat spirit to do that. I think the people we have are the best qualified in that line. Of course, as you say, if it is used back in a kind of reserve line or in a reserve position or a concentration area but that you wouldn’t be up against right away. H: I don’t think you would land at eight o’clock in the morning and you would drop it at six o’clock, out the day before, even from the tactical standpoint without regard to when it fails to go off or something like that.

S: Another thing you may be likely to consider is that while you are landing you might not want to use it as it could be a dud. It is not something that you fool around with.

Atomic bombs: “not something that you fool around with.” Truer words never spoken, eh? I’m not sure how they were planning to measure acute, on-the-ground radioactivity in the places they’d just bombed, given that the war wasn’t over yet. (They did send over people in September 1945 to learn about things like that, after the war was over.) In any case, imagine if they had, haphazardly, sent American troops through recently atomic-bombed zones as part of the invasion. What would the legacy of American use of the bombs been, then?

The concern with the possibility of a “dud” is also counter to the usual historiography. What if one of them hadn’t gone off? The Los Alamos folks had calculated that the possibility of a bomb failing was pretty high; neither of them did fail, so it’s easy to see them as resounding successes, but the sample size here (n = 3) is awful small.

H: I would appreciate if you would discuss that angle with General Groves. I would like to have his slant on it. That is the question, how do we employ it and when do we employ it next? It has certainly served its purpose, those two we have used. I don’t think it could have been more useful than it has. If we had another one, today would be a good day to drop it. We don’t have it ready. Anyhow within the next ten days the Japanese will make up their minds one way or the other so the psychological effect is lost so far as the next one is concerned in my opinion, pertaining to capitulation. Should we not lay off a while, and then group them one, two, three? I should like to get his slant on the thing, General Groves’ slant.

Again, the possibility of “pour[ing]” them out in groups, linked towards guessed psychological reactions. I also find Hull’s comment about “today” (August 13) being a good day to “drop it” interesting. August 13 was about four days after the last bomb; presumably Hull’s “feel” for this was that every three or four days would have been a good rhythm for atomic bombing.

Tags: 1940s, Hiroshima, Historiography, Manhattan Project, Speculation