What kind of warning did Japanese citizens have before dropping atomic bombs in World War II?
6 Discussions

Due to the secrecy surrounding atomic fission research only vague warnings could be given in leaflets dropped by Allied bombers. Even if a warning was explicitly given since the technology to create such a weapon was largely unknown to the population and no such kind of explosive was known to closely resemble an atomic bomb most would have regarded it as war propaganda. Einstein's E=MC^2 is what gives nuclear reactions more energy than chemical reactions but most Japanese like the Germans in the early 1940s would have dismissed Einstein's work as "Jewish science".

According to the Atomic Heritage Foundation website the main text of the Hiroshima warning leaflets was:


America asks that you take immediate heed of what we say on this leaflet.

We are in possession of the most destructive explosive ever devised by man. A single one of our newly developed atomic bombs is actually the equivalent in explosive power to what 2000 of our giant B-29s can carry on a single mission. This awful fact is one for you to ponder and we solemnly assure you it is grimly accurate.

We have just begun to use this weapon against your homeland. If you still have any doubt, make inquiry as to what happened to Hiroshima when just one atomic bomb fell on that city.

Before using this bomb to destroy every resource of the military by which they are prolonging this useless war, we ask that you now petition the Emperor to end the war. Our president has outlined for you the thirteen consequences of an honorable surrender. We urge that you accept these consequences and begin the work of building a new, better and peace-loving Japan.

You should take steps now to cease military resistance. Otherwise, we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.



Because your military leaders have rejected the thirteen part surrender declaration, two momentous events have occurred in the last few days.

The Soviet Union, because of this rejection on the part of the military has notified your Ambassador Sato that it has declared war on your nation. Thus, all powerful countries of the world are now at war with you.

Also, because of your leaders' refusal to accept the surrender declaration that would enable Japan to honorably end this useless war, we have employed our atomic bomb.

A single one of our newly developed atomic bombs is actually the equivalent in explosive power to what 2000 of our giant B-29s could have carried on a single mission. Radio Tokyo has told you that with the first use of this weapon of total destruction, Hiroshima was virtually destroyed.

Before we use this bomb again and again to destroy every resource of the military by which they are prolonging this useless war, petition the emperor now to end the war. Our president has outlined for you the thirteen consequences of an honorable surrender. We urge that you accept these consequences and begin the work of building a new, better, and peace-loving Japan.

Act at once or we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.


Source:  https://www.atomicheritage.org/key-documents/warning-leaflets

Not believing an atom bomb was possible before 1945 would have been reasonable. The science fiction author H.G. Wells had fictionalized atomic weapons decades earlier and the scientist Ernest Rutherford described the idea of arnessing atomic power as "moonshine".


The Americans dropped over 5 million leaflets over the target cities prior to dropping the Atomic bombs.

This is a translation from an original leaflet that I found whilst hunting for the facts.

Leaflet obtained from damninteresting.com

 “Read this carefully as it may save your life or the life of a relative or friend. In the next few days, some or all of the cities named on the reverse side will be destroyed by American bombs. These cities contain military installations and workshops or factories which produce military goods. We are determined to destroy all of the tools of the military clique which they are using to prolong this useless war. But, unfortunately, bombs have no eyes. So, in accordance with America’s humanitarian policies, the American Air Force, which does not wish to injure innocent people, now gives you warning to evacuate the cities named and save your lives. America is not fighting the Japanese people but is fighting the military clique which has enslaved the Japanese people. The peace which America will bring will free the people from the oppression of the military clique and mean the emergence of a new and better Japan. You can restore peace by demanding new and good leaders who will end the war. We cannot promise that only these cities will be among those attacked but some or all of them will be, so heed this warning and evacuate these cities immediately. 

In accordance with the leaflets a radio station was broadcasting similar messages fro a radio station in Saipan. More leaflets were dropped again. As you can read from the leaflet is is quite specific stating the reasons behind the bombing as they were targeting military installations. The Americans didn't need to warn them as they had no prior warning to Pearl harbor which pulled America into the war in the first place.

5 days later the American s dropped the bomb on Hiroshima, then 3 days later Nagasaki was bombed.

They were warned at least and not really much more could be done. It did have a huge impact on the war saving millions of allied lives.

They were not warned. But not even the American creators of the so-called "Manhattan Project", more determined to end the hateful war, than in the in-depth study of what was not a simple bomb, only with more destructive power, and that left radioactivity they knew nothing. In fact, the explosion (misnamed so because it is not an explosion, but a physical chain reaction caused by the rupture of an atom whose pieces break another and so consecutively releasing in that process an amount of energy that can reach the temperature of the solar surface at the center of the reaction), was contemplated in the tests at a distance where they were reached by radioactivity and their subsequent and strange deaths and diseases is what led to investigate them in more depth and you know how they work, that is why we are already in the 6th generation of these devices with a destructive power and not by explosion but by disintegration would be the closest thing. 

The released energy is transformed into a kind of current of thousands of degrees of temperature that melts everything as far as it reaches. Nobody will have heard of the collection of corpses or limbs after the "explosion" of one of these devices and that has volatilized them into invisible particles, which is radioactivity, which means "disintegration". The most powerful explosive known during the Second Great War was TNT (Trinitrotoluene) and this was taken as a reference to calculate the destructive power of an atomic bomb represented in the Kiloton, equivalent to the explosive power of 1000 Tm of TNT, or  a million kilos of this explosive. 

The bombs of Hiroshima and Nagasaki had a power of between 21 and 23 kilotons, that is, 23 thousand tons, 23 million kilos. Its operation was that, before touching land, a conventional explosion breaks an atom and when it has touched the ground, the physical chain process is unleashed. The closest ones before volatilizing would see a light like a gigantic photographic flash that left even the shadow engraved. Contrary to what is believed, they do not produce the characteristic sound of an explosion but rather as a kind of vibration that nobody notices that it is an atomic bomb. The Kt. it is not used, but the Megaton, equivalent to 1000 Tm of kilotons and the current ones with which the nuclear powers count around 5 megatons, that is 5,000,000,000,000 (5 billion) Ks. of TNT.

Before the besieging of Japanese urban areas American air ship dropped "LeMay Leaflets," named after Army Air Force General Curtis LeMay which commonly resembled this:

The front side contains the name of urban areas in Japan that would be besieged while the switch side contained this message "Read this painstakingly as it might spare your life or the life of a relative or companion. In the following couple of days, a few or the majority of the urban areas named on the invert side will be annihilated by American bombs. These urban communities contain army bases and workshops or production lines which deliver military merchandise. We are resolved to pulverize the majority of the apparatuses of the military inner circle which they are utilizing to delay this futile war. In any case, tragically, bombs have no eyes. Thus, as per America's helpful strategies, the American Air Force, which does not wish to harm blameless individuals, now gives you cautioning to clear the urban areas named and spare your lives. America isn't battling the Japanese individuals yet is battling the military faction which has subjugated the Japanese individuals. The peace which America will bring will free the general population from the abuse of the military coterie and mean the rise of another and better Japan. You can reestablish peace by requesting new and great pioneers who will end the war. We can't guarantee that just these urban communities will be among those assaulted however a few or every one of them will be, so regard this notice and clear these urban communities promptly."

As indicated by the CIA, flyers like this one were dropped on Hiroshima and Nagasaki before the nuclear bombings.

These flyers were dropped from changed 500 pound ignitable bombs with each containing a great many handouts, with each plane having the capacity to convey around 40 of these adjusted canisters. They were imprinted on Saipan and made by the Office of War Information, and 63 million were dropped on Japan to 35 urban areas.

This popular photograph of aircraft passing Mt Fuji really demonstrates B29s on the way from Saipan to convey flyers to Japanese urban communities

After the nuclear bomb was dropped on Hiroshima, new leaflets were printed with George Caron's (tail heavy weapons specialist on the Enola Gay) photo of the mushroom cloud transcending Hiroshima.

With the content : "TO THE JAPANESE PEOPLE:

America solicits that you take prompt regard from what we say on this handout.

We are in control of the most dangerous touchy at any point contrived by man. A solitary one of our recently created nuclear bombs is really the equal in hazardous capacity to what 2000 of our mammoth B-29s can bear on a solitary mission. This horrendous reality is one for you to contemplate and we seriously guarantee you it is dismally exact.

We have quite recently started to utilize this weapon against your country. In the event that despite everything you have any uncertainty, make request with respect to the end result for Hiroshima when only one nuclear bomb fell on that city.

Before utilizing this bomb to pulverize each asset of the military by which they are dragging out this futile war, we ask that you presently appeal to the Emperor to end the war. Our leader has sketched out for you the thirteen outcomes of a fair surrender. We encourage that you acknowledge these results and start crafted by building another, better and peace-cherishing Japan.

You should make strides presently to stop military obstruction. Else, we will unflinchingly utilize this bomb and all our other better weapons than quickly and commandingly end the war.


It ought to be noted however that these handouts were not accepted to have been dropped on Nagasaki before the second nuclear bomb was utilized on it.

All in all, yes the Japanese residents received reasonable cautioning about besieging of urban areas, however until after Hiroshima they didn't get any notice particularly identifying with the nuclear bomb. Despite the fact that the possibility of emptying the whole Japanese urban populace was clearly inconceivable, and the leaflets were similarly utilized as notice and publicity (it unquestionably wasn't consoling to seek shelter from an air attack and have nothing happen just to venture out from the all unmistakable and read flyers expressing you will be shelled), the fact of the matter is cautioning was given to Japan before air strikes, particularly likewise Hiroshima and Nagasaki.

A debt of gratitude is in order for perusing and expectation this makes a difference!


Adjustment - the B29 could convey more like 40 not 30 500 pound bombs (20,000 lb add up to bombload)

Extra Information

To those getting some information about when these handouts were dropped on Japan-as per the CIA report which I have connected beneath, flyers were printed straightforwardly on Saipan after the US took the island in July of 1944, however does not give a particular time span referencing concerning when they were dropped. Considering the advanced name "LeMay Leaflets," it is likely the handouts were dropped from mid 1945 (when LeMay took order of plane direction for japan or February when low elevation firebombing versus high height high unstable besieging started) to the finish of Japanese surrender as we probably am aware from the Hrioshima pamphlets - on the off chance that anyone has more data please let me know and I will include it if conceivable.

For those pondering about different ways the Japanese were cautioned about the war all in all, a radio station was likewise set up on Saipan that communicate purposeful publicity to Japan and Japanese held islands. This likewise contained news about the advancement of the war, as even essential data was intensely blue-penciled by the Japanese military ( For instance after the Battle of Midway the surviving group that were injured were disconnected from different patients in healing centers and unharmed teams "vanished" into high force battle posts where generally passed on)

For those pondering about the impact of the flyers on the Japanese Government and Civilians - For regular people again the handouts were double reason as notice and promulgation, however as indicated by after war surveys(likely US Strategic Bombing Survey, yet I don't have the foggiest idea about the correct report - there are actually 108 volumes for Japan and I could sincerely not likely discover it-I just know these particularly about flyers exist per the CIA report), numerous Japanese regular folks prepared to rapidly leave their homes because of flyers .

With respect to the warmonger government, as Richard Grams asked for the impact of handouts on the legislature was basically nothing. Obviously however it was illicit to be found with the handouts, this was to a greater extent a proportion of faithfulness ensurance and control of the Japanese populace. Indeed, even the fire besieging of a large portion of Japan's urban areas had just some impact on a great part of the military's brain about surrender - the Japanese were actually setting up the whole populace to battle the Allies if there should arise an occurrence of an intrusion (however we as a whole know how well this would have gone). Additionally, even after both nuclear bombs had been dropped with a desire for a boundless American supply (the reason Hiroshima and Nagasaki bombings were so near one another to influence the Japanese to trust we would not come up short on bombs), and the Russian affirmation of war on Japan, the Japanese majestic war board was as yet part 3– 3 on whether to surrender and it took Hirohito's own mediation to arrange the gathering to surrender. Indeed, even with this, the Kyujo overthrow was endeavored with the end goal to stop the surrender. The leaflets themselves nonexistently affected the administration, and the bombings, both nuclear and customary, finished the war as a result of a mix of Russian presentation of war and the loss of Manchuria, the discount pulverization of the Japanese naval force and Air Force (in late 1945 we had a greater number of boats than the Japanese had planes), the inversion of almost all of japans increases regional since 1932, control of Japanese "home domain" (Okinawa and Iwo Jima), Hirohito's own intercession, and the bombarding of Japan. In short yes the besieging of Japan played a major job in consummation the war, however it is just a single of numerous variables that is regularly tragically neglected.

I just wanted to pop in and say, what an interesting question!! I just saw it so clicked to see the answer. This is what I love about musing :-)

Replied to comment 3 years ago

I think you meant to post this answer for a different question. :-)

Hide replies