Was there a demonstration A-Bomb?

I vaguely remember during high school hearing that the US did some kind of demonstration atomic bomb test, (perhaps in the open ocean?) to show the Japanese military that we meant business BEFORE we dropped one on Hiroshima. Was that really the case or did I dream the whole thing up?

Project Trinity.

Okay… but were the Japanese invited to attend?

Given that a state of war existed between us and them, it seems unlikely that we would invite them to the first live test of a new munition, no matter how powerful.

There was no demonstration/warning given to the Japanese prior to the bombing of Hiroshima other than the cryptic promise of “prompt and utter destruction” in the Potsdam Declaration.

You dreamed it up. By mid-1945 US had made only 3 bombs; one was tested under extreme secrecy at Trinity, the other two were dropped on Hiroshima and Nagasaki.

Given the number of innocents killed I would have thought there would have been some kind of demonstration, after which the Japanese chose to take their chances. Apparently there was no demonstration.

The Japanese did not immediately surrender after the Hiroshima bomb, evidently a second demonstration was needed on Nagasaki to convince them.

I think you are misremembering the Bikini Atoll and others that occured AFTER the war.

Besides, what if the damn thing didn’t work? :slight_smile:

Try and insist on “unconditional surrender” then.

The United States had already firebombed Axis cities (most notably Dresden and Tokyo). The ensuing firestorms from those and similar attacks killed hundreds of thousands of civilians. At the time the atomic bomb was seen merely as a more efficient way of destroying a city.

I don’t think anyone really cared. There were already millions dead from the war. We were still pretty pissed at Japan anyway for the whole Pearl Harbor thing. Japan and the Allies pretty muched viewed each other as round-eye barbarians / yellow monkeys, and the last thing the US wanted to do was possibly lose the element of surprise or risk encouraging the Japanese if the test failed, forgetting that we only had a few bombs anyway and not to mention that we pretty much had burnt Tokyo and other cities to the ground with non-nuclear weapons anyhow.

No, it never happened. But it was one scenario that some in the military proposed: Do a demonstration bombing on some uninhabited target, so that no one would die, but the Japanese would see we had some big mojo, and compel their surrender.

It was ultimately decided that we could not risk that the Japanese might think it some trick or that the psychological impact might be enough, etc. (whereas, if you kill 70,000 of their citizens and flatten one of their cities, no one can dispute the evidence), esp. since we had so few bombs. Also, we had only ever set one bomb off, so we still really wanted real-world data on what happened when you bombed a city, not just a desert.

Well, first of all, the idea that the Allies had a duty to inform the Japnese of the existence of an atomic bomb suggests a fairly naive understandign of the nature of war.

Secondly, the idea that mass devestation of a city was an idea the Japanese hadn’t contemplated is just flat out wrong. The fire-bombing of Tokyo on March 9, 1945 killed more people (100,000) than the atomic bomb dropped on Hiroshima (70,000).

Thirdly, as has been discussed in one of the other threads on the subject you started today, the Japanese may not have known we had a working bomb, but they certainly knew the concept and knew that we were trying to build one.

As others have mentioned, it was one scenario that was ultimately rejected for various reasons. In the event, it clearly would not have worked - it took a second bombing even after the “demonstration” of Hiroshima to get the Japanese to surrender.

It must remembered that the unique horror we have about nuclear weapons today did not exist in 1945. That aversion was generated in large part by seeing the effect of radiation poisoning on civilian populations. As has been said, at the time the A-bomb was seen as just a much more efficient way of flattening a city.

Few is correct. It would be six months at least before the US could deploy another bomb after the first three. Getting U-235 and plutonium back then was a major hassle (well…still is a hassle but of course the process is much better understood and they are a lot better at it today).

Also, don’t forget that Gadget (the first bomb) and Fat Man were plutonium bombs. They tested Gadget to have a reasonable belief that Fat Man would work but there was only the one uranium bomb (Little Boy) which was “tested” over Hiroshima. Little Boy was a simpler design and was expected to work but with something like this who really knew? If all that happened in a demonstartion test to the Japanese was a few thousand pounds of TNT going off the Japanese would have been underwhelmed to say the least.

The possibility of mounting a demonstration was discussed prior to use, but largely informally and the idea was rejected, possibly rather quickly.

Specifically, the proposal emerged from a group of Manhattan project scientists working in the Met Lab in Chicago, which was one of the major research centres on the project. Amidst a groundswell of unease as the project neared completion and as the surrender of Germany removed their main motivation for having got involved in the first place, the Chicago scientists began to call for a rethink. The formal result, at the instigation of the lab director, Arthur Compton, was an in-house committee of physicists that produced something called the Franck Report. This attempted to forecast what the consequences of nuclear weapons would be in the postwar world and hence assess the options available. Their proposal was a Trinity-style test to which representatives of all the United Nations countries (not quite the UN in it’s current form, but the original version thereof) would be invited. The results of this test would be made fully public. They obviously hoped that this would be enough to persuade the Japanese government to surrender. If not, they envisaged that both the UN and the American public would then endorse the use of the new weapon against the intransigent Japanese.
These conclusions were widely endorsed by the scientists working in Chicago, who then hoped to convince Oppenheimer. Instead, he ignored the Frank Report, a petition and various direct approaches by his colleagues in Chicago; given the conditions of compartmentalisation, it seems that virtually no-one else at Los Alamos got to know of the protests.
Where the Chicago idea was raised during the final stages of the decision-making process was in the Interim Committee, which appointed by Secretary of War Stimson to consider issues of how to use the weapon. Most of its members were politicians or scientists who’d ascended to become wartime administrators. But also participating in meetings was a Scientific Advisory Panel: Oppenheimer, Enrico Fermi, Ernest Lawrence and Compton. The Committee had been formally sent the Franck Report and it’s known that a few of the members had discussed it, but the Report was never officially raised as such in any of the meetings. However, Lawrence (or possibly Compton) raised the suggestion of a demonstration over lunch during a crucial meeting of the Committee on 31/5/45. He appears to have done so because he was in sympathy with the idea. Compton, representing the Chicago lab, was also in favour of it being considered.
Accounts of what happened next vary. The idea may have been dismissed over lunch. The Panel, particularly Fermi, may have considered the practical issues involved in it overnight before rejecting it. Compton’s account - in his Atomic Quest (Oxford, 1956) - is the most detailed I’ve seen, though not neccesarily the most unbiased. According to it, the Advisory Panel spent a weekend in the middle of June at Los Alamos arguing about the practicalities, reluctantly concluding that any realistic demo was unlikely to end the war and submitted a report to this effect to the Committee on June 16th. In his version, Lawrence in particular took a lot of convincing that the idea wouldn’t work.
As summarised by Compton, the main arguments against were twofold. The chances of a dud were too high, and the risk of hostile interference too great, for any demo to be conducted on Japanese territory. But if the demo was done elsewhere then the likelihood was that the Japanese military was unlikely to be convinced. They could, for instance, possibly envisage that it had been faked with lots of conventional explosives, etc.

Whether adequate consideration was given to the idea is more a matter of opinion and, as such, something that there’s unlikely ever to be agreement on.

As I’ve already noted in one of the other threads tonight, not true.

Besides which, these were the same people who bombed Pearl Harbor, and estimates of casualties from Operation Olympic were in the millions. Very few Americans cared one little bit if Japanese cities got erased. As others have noted, we were doing quite a job on them with firebombs already. As Bull Halsey put it - by the time he was finished, the only place Janapese would be spoken was in Hell.

This isn’t true. Even combining the most liberal casualty estimates for Operations Olympic and Coronet, reaching 1 million would be difficult.

They were pretty pissed. The Bataan Death March, the Rape of Nankeen (sp) the execution of prisoners from the Doolittle Raid come to mind.