Q:What was the original dome used for

·  It was the Hiroshima Prefectural Industrial Promotion Hall, which opened in August 1915 to display and sell local products and to hold various exhibitions.  It was like a department store.  As the building was designed by a Czech architect, it was a unique European style building and very popular among citizens.

·  Products sold there included oysters, agricultural products, and woodworks, such as furniture (chest), kitchenware (tray) and musical instruments (koto).

·  During the war, it was used by governmental organizations.  It is said there were about 30 persons working in the building that morning, and all of them perished.

 Q:Why did Japan start the war

    Japan was not a nation blessed with many natural resources as was the U.S., and other enemies of that nation. In order to secure those additional raw materials, such as rubber, tin, and petroleum, among others, the war leaders decided that conquest of other nations was a solution, and began by attacking China, which in actuality was the (early) start of the war.


    At the time, China was a virtual colony for many European nations, including England, France, Netherlands, and the US as well as Japan. Other colonies in Asia included Vietnam for France, Philippines for US, Indonesia for Netherlands, and so on. As the great powers competed for regional interests, Japan was quickly gaining ground from obtaining German concessions after participating on the allied side in WWI. The United States did not view Japan's intrusion into China as favorable to its own interests in the area, and thus economic frictions between US and Japan arose. At the time, Japan relied 80% of its resources, including oil, indispensable at the time, to the US. The US began throttling its exports to Japan, and pressured its allies to do the same (such as the Netherlands and Mexico, which Japan sought to purchase oil as alternative sources).


   The United States froze all Japanese assets in the US and slapped an embargo on exports to Japan, among other things. Although the Japanese did pursue legitimate diplomatic means of resolving the tension throughout this time, part of this southern strategy was to take over the Philippines, which were essentially a ward state under the United States.


    In November of 1941, the Japanese agreed that if negotiations failed, they would go to war with the United States. To do so, they would have to contend with Pearl Harbor, which had a significant buildup of US naval forces. The Roosevelt Administration was focused on Europe, and essentially rebuffed the Japanese's negotiations. The Japanese then decided to attack Pearl Harbor, preemptively, which would theoretically disable the US fleet enough for them to continue their southern strategy.

 Q:What do you think of Pearl Harbor attack

·  I believe, without the Pearl Harbor attack, the pacific war should have begun sooner or later. Conflict between Japan and the U.S. was so intense.

·  Hiroshima and Honolulu, where the Pearl Harbor is, became sister cities in 1959 to cooperate for the world peace. It was a symbolic event of reconciliation between citizens of the two nations.
New American:
Pearl Harbor: Hawaii Was Surprised; FDR Was Not, Written by James Perloff 
"Comprehensive research has shown not only that Washington knew in advance of the attack, but that it deliberately withheld its foreknowledge from our commanders in Hawaii in the hope that the "surprise" attack would catapult the U.S. into World War II." 
Q:Were Japanese people against the war

·  People were taught and believed it was the right war for Japan to help Asian countries.  American and British were very brutal and Asian people were badly suffering.

·  Japanese government and the military authorities controlled civilians very tight.  If a person openly opposed against the war, the person was called “a traitor” and arrested.
Q:Why was the atomic bomb dropped on Japan 
As General Dwight Eisenhower said, Japan was at that very moment seeking some way to surrender with minimum loss of face, and ‘it wasn’t necessary to hit them with that awful thing.’ So if Japan was ready to surrender, why were atomic bombs dropped on Hiroshima and Nagasaki? A significant factor in the decision to bomb was the US’s desire to establish its dominance in the region after the war. Those planning for the post-war situation believed that this required US occupation of Japan, enabling it to establish a permanent military presence, shape its political and economic system and dominate the Pacific region without fear of Japanese resurgence.  
Full text https://cnduk.org/why-the-atom-bomb-was-dropped-on-japan-2/ 

 Q:Was there any warnings of the A-bombing

·  No, there were only general warnings which said, if Japan did not surrender immediately, you would get more intense air raids.

·  American military authorities had decided not to give a specific warning in advance.  Because they thought, if a specific warning was issued, Japanese forces might prepare to intercept American bombers, evacuate from the target area, or bring American POWs there.

 Q:Was the use of nuclear weapons illegal

·  There was no international law which explicitly said it was illegal to use nuclear weapons.  But, a wartime international law adopted in the 1889 Hague Peace Conference prohibits from use of weapons which inflict unnecessary agony on persons.

·  In July 1996, the International Court of Justice (ICJ) (in Hague, Netherlands) formed a judgment that the threat or use of nuclear weapons would be a violation of international law applicable to armed conflict. 

 At the time of bombing ]

 Q:Why wasn’t the warning issued

·  At the last stage of the Pacific war, American bombers frequently came over Japan in a big formation.  Planes flying in a small number were sometimes overlooked.

·  Japan’s bomber watch system was tricked by a tactic of the U.S. forces.  One hour before the A-bomb attack, a plane flew over Hiroshima from west to east. Analyzing radio communication of the plane, it was thought that the plane was to check weather for a bombing and bombers would follow the plane.  As bombers always had come on the same direction as a weather-scouting plane, a watch system in the area focused on west.  But, the bomber carrying the A-bomb (Enola Gay) came from east.  When the system found Enola Gay, it was too late.  The A-bomb exploded before a warning was issued.

 Q:Why did they use the two different types of atomic bombs

·  They had no confidence to develop an atomic bomb in time, so they attempted two ways.  Finally, they had succeeded in both ways.  They made one uranium bomb and two plutonium bombs.  As the mechanism of a plutonium bomb is complicated, they needed a test to see if it works.  One plutonium bomb was used for a test, and others were used to attack Hiroshima and Nagasaki.

 Q:Why did the U.S. military make the atomic bomb explode in the air

·  It was intentional.  The U.S. military thought, because the bomb had immense power, violent blast would reach further when it detonated high up in the air.  The bomb exploded at 600m above the ground, and created such devastation as intended.  It’s said, if the bomb detonated on the ground, a big hole of 300m diameter and 50-150m depth would have been created.

·  The U.S. military knew radiation and heat rays would be emitted from the A-bomb as well as blast, but they didn’t know strength of their destructive power.  So, they counted only on blast to attack the city.
Q:What’s the difference the explosive power between Hiroshima bomb and Nagasaki bomb?

·  Power of Hiroshima bomb was 16Kton (TNT equivalent), and Nagasaki bomb was 21Kton.  Nagasaki bomb was 1.3 times more powerful than Hiroshima one.

·  In Nagasaki, the bomb exploded at the point over 3km off the target.  As it was less populated area, the number of casualties was much less than in Hiroshima.

 after the bombing ]

 Q:Did Japanese people know that the bombs were atomic bombs soon after the bombing

·  No.  On the next day, Imperial Headquarters merely announced that Hiroshima was somewhat damaged by a new type bomb.  But they didn’t mention it was an atomic bomb until after the war.

·  Just after the war, Japan was occupied by the allied powers.  Occupation forces were afraid that, if devastating damages caused by the A-bomb became widely known in Japan, people might have ill feeling against American.  It might disturb their occupation operations and drive Japan to Soviet Union group.  So, they imposed a press code which prohibited reporting about the A-bombing.

 Q:How long did the press code last

·  It was in effect until the peace treaty between Japan and the U.S. became effective in Apr., 1952.

·  During May 1946 and Nov. 1948, Tokyo military court was held by the allied powers.  Over 20 Japanese leaders were found guilty of causing the war.  And, it was considered Americans were not to be blamed for the result of the war.  In that situation, application of the press code was getting eased.

 Q:What kind of symptoms did the victims develop

·  Symptoms of acute disorder include high fever, diarrhea, nausea, vomiting blood, exhaustion, hair loss and so on.

·  People including doctors didn’t know about radiation disease, so patients were diagnosed as dysentery and isolated in closed areas.

 Q:How long did residual radiation stay

·  Residual radiation did not stay long in Hiroshima, unlike other radiation contaminated areas such as Marshall Islands, Chernobyl and Gulf War area.  It became negligible within 2 weeks or a month.

·  The Japanese Government certifies a person as an A-bomb survivor, in case the person entered an area within 2km of the hypocenter in two weeks after the explosion.  It means residual radiation became negligible after 2 weeks from the bombing.

·  Residual radiation includes induced radiation and radioactive fallout.  Induced radiation which was created in soil and buildings by collision of neutrons became negligible in 100 hours.  Radioactivity of fallout was very weak, but when it entered human body through mouth or nose, it would give serious damages.

 Q:Why didn’t residual radiation stayed long in Hiroshima

·  There are three major reasons.  Radiation emitted from the Hiroshima A-bomb was much less, comparing H-bomb tests or the Chernobyl nuclear plant accident. Secondly, the bomb exploded high up in the sky, and heated air went up to create a huge mushroom cloud.  Radioactive dust spread over the cloud, and density of radioactive fallout became very light.  Thirdly, a big typhoon(#) attacked Hiroshima a month later, and washed radioactive materials away.

 (#) The Makurazaki Typhoon which attacked Japan on Sept. 17-18.  Hiroshima heavily suffered.  Over 3,700 persons were killed or missing.  It was one of the three biggest typhoons in the Showa era with Muroto (1934.9) and Isewan (1959.9) Typhoons.

 Q:Did the survivors get enough support

·  No.  Because of the press code, which had been enforced by the allied forces and was effective until 1952, tragic suffering in Hiroshima was not officially discussed in Japan and survivors didn’t get special support for long.

·  A law for medical support was enacted in 1957, and a law for living benefit in 1968.  It was over two decades after the bombing.

 Q:Did the U.S. compensate for the war damage

·  The U.S. didn’t compensate for the war damage at all, including A-bomb damages. According to the judgment of Tokyo Court, it was considered Japan’s leaders were fully responsible for causing the devastating damage.

·  The U.S. helped a lot Japan for its reconstruction.  They thought, as Japan was desperate for aid for restoration, if the U.S. didn’t give hands, Japan might go to the Soviet Union for help.

 Q:What happened to Japanese leaders after the war

·  In the Tokyo Court held after the war, over 20 Japanese leaders were found guilty of a “crime against peace” or a “crime against humanity”, and sentenced to death or to life.  In total, 5,700 Japanese were brought into military courts, and 1,000 of them were killed.

·  The U.S. allowed the Emperor stay in the position as a symbol of Japan, for the people of Japan were desperate to keep the Emperor.

 Q:Did Japan compensate the countries

·  Japan formally compensated 4 countries (Philippines, South Vietnam, Cambodia and Laos).  Many other countries gave up their claim rights.  In return, Japan offered free fund supplies to most of those countries.  The compensations had been officially settled by 1977 to all suffered countries except North Korea.

·  Japan’s compensations were not paid to individuals, but they were used for social infrastructures, such as building dams and ironworks.


 Q:Can you detect radiation now

·  Yes, though it’s in a very special case.  Several years ago, a scientist detected radiation from marks of black rain, which is exhibited in the radiation corner of this museum.  He had to use advanced equipment of super high precision, because radiation level is very low.  It’s impossible to detect the A-bomb’s residual radiation in ordinary circumstance.

 Q:Is there any radiation effect on second generation

·  An official statement from the Japanese government says there is no radiation effect on the second generation.

·  By the request of the second generation, a large scale study has just started.  It may take some time to conclude the study.

 Q:Do the survivors hate Americans

·  That may depend on individuals.  I believe most survivors don’t have grudges against the U.S. no more.  They think it was a war and a nuclear weapon that caused such suffering, and wish to hand over a world free of war and nuclear weapon to their descendant.  They think grudges create only a chain of retaliations.
  According to a research done by NHK in 2015, only 23 % of the survivors have grudge against  the U.S. , but they seldom express their feelings. 

·  Survivors are now strongly blaming the U.S. for they are not aggressive to give up nuclear weapons.  That is their obligation agreed upon in the NPT (Nuclear Non-Proliferation Treaty).  The U.S. is still conducting nuclear tests and developing a new type of nuclear weapons.

 Q:Do Japan have nuclear weapons

·  No.  Japan has the Three Non-Nuclear Principles, which are no production, no possession and no introduction of nuclear weapons.

·  According to the Japan-U.S. Mutual Security Treaty, the U.S. must consult the Japanese government before bringing any nuclear weapons into Japan.  Japanese government says U.S. battleships visiting Japan’s port are not equipped with nuclear weapons because they don’t tell they have ones.

 Q:Do you think that a nuclear deterrent works?

·  No. As nuclear technology is advancing, nuclear weapons will become smaller and handier.  When terrorist groups get those weapons, a nuclear deterrent won’t work.
 Q:Did any American presidents visit the museum

·  On May 27, 2016, Barack Obama  became the first sitting U.S. president to visit Hiroshima, where he called for a "world without nuclear weapons" during his remarks at the city's Peace Memorial Park.
Critical views of President Obama’s speech in Hiroshima
Transcript of President Obama’s speech
· In May 1984, Jimmy Carter, the 39th President of the U.S.   visited Hiroshima after leaving of office.

   (by Ken'ichi Harada, volunteer guide of Hiroshima Peace Memorial Museum)

Q: Were any Americans killed by the A-bomb?
Yes, 12 POWs were killed. Here is a sruvivor's testimony.
DATE WITH THE ‘LONESOME LADY’ A Hiroshima POW Returns by Lt. Tom C. Cartwright

 Q:What percent of the U.S. population justify the A-bombing?

Sixty-four years after America dropped atomic bomb on Hiroshima and Nagasaki, American voters say 61 – 22 percent, with 16 percent undecided, that it was the right thing to do, according to a Quinnipiac University poll released today.

Weaker support for President Harry Truman’s decision is 49 – 29 percent among Democrats, 51 – 27 percent among women, and 50 – 32 percent among voters 18 – 34 years old, the independent Quinnipiac University poll finds.

Voters over 55 years old approve 73 – 13 percent, while voters 35 to 54 approve 60 – 23 percent. 

Strongest support is 74 – 13 percent among Republicans and 72 – 17 percent among men.

While Protestants, Catholics and evangelical Christians all support the bombing by about 70 -15 percent, while Jews support it 58 – 26 percent.
The whole text:http://y-sonoda.asablo.jp/blog/imgview/2009/08/06/b6bd6.jpg.html 

Pew Research Center survey (April 7, 2015)

One event during WWII – the U.S. dropping atomic bombs on the Japanese cities of Hiroshima and Nagasaki in August 1945 – has long divided Americans and Japanese. Americans, in surveys with similar wording, have consistently approved of this first and only use of nuclear weapons in war and have thought it was justified. The Japanese have not.

In 1945, a Gallup poll immediately after the bombing found that 85% of Americans approved of using the new atomic weapon on Japanese cities. In 1991, according to a Detroit Free Press survey conducted in both Japan and the U.S., 63% of Americans voiced the view that the atomic bomb attacks on Japan were a justified means of ending the war; only 29% thought the action was unjustified. At the same time, only 29% of Japanese said the atom bombing was justified, while 64% thought it was unwarranted.

In the current Pew Research Center survey, 56% of Americans still believe the use of nuclear weapons was justified; 34% say it was not In Japan, only 14% say the bombing was justified, versus 79% who say it was not.

Not surprisingly, there is a large generation gap among Americans in attitudes toward the bombings of Hiroshima and Nagasaki. Seven-in-ten (70%) Americans 65 years of age and older say the use of atomic weapons was justified, but only 47% of 18- to 29-year-olds agree. There is a similar partisan divide: 74% of Republicans but only 52% of Democrats see the use of nuclear weapons at the end of WWII as warranted. Men (62%) more than women (50%), and whites (65%) more than non-whites (40%), including Hispanics, say dropping the atomic bombs was justified.



What made Japan decide to surrender?

 Before the bomb was used, U.S. intelligence officials believed the war would likely end when two things happened: When the Soviet army attacked Japan and when the U.S. let Japan know their Emperor could stay on as a figurehead.

 The Soviet Union officially declares war on Japan as agreed in Yalta Conference, on August 9, pouring more than 1 million Soviet soldiers into Japanese-occupied Manchuria, northeastern China, northern Korea, Karafuto, and the Chishima Islands. The rapid defeat of Japan's Kwantung Army helped in the Japanese surrender.

The U.S. told Japan the Emperor could remain on August 12. "The ultimate form of government of Japan shall, in accordance with the Potsdam Declaration, be established by the freely expressed will of the Japanese people.”

Japan surrendered on August 14.

Boston.com: Why did Japan surrender? 
"Sixty-six years ago, we dropped a nuclear bomb on Hiroshima. Now, some historians say that’s not what ended the war." 
Global Research:The Real Reason America Used Nuclear Weapons Against Japan. It Was Not To End the War Or Save Lives.

:How many people die?

The A-bomb devastated nearly all administrative agencies and destroyed official documents. Thus, the exact number of death due to the atomic bombing of Hiroshima remains unknown. Many victims were never identified.

According to a document submitted by the city of Hiroshima to the United Nations in 1976 entitled “For the Elimination of Nuclear Weapons and the Reduction of All Armed Forces and All Armaments,” an estimated 140,000 (±10,000) people died as a result of the A-bomb between August 6, 1945, and the end of December.

Not only Japanese but approximately 20,000 Koreans, 12 American POWs and 8 Asian students studying at Hiroshima University died.

After that, many survivors died of cancer or some other diseases, but it is very difficult to prove the relation between their diseases and radiation, and moreover, even now lots of survivors are not acknowledged as survivors and can’t get “survivor’s health book.”

:What is "A-bomb survivor' book"?
- click this title
2420 in South Korea, 850 in the United States, 140 in Brazil and 3660 in other 30 countries (as of March ,2005)

Q:How many victims, who were within 500m from the hypocenter, live now?
Twelve victims (2 men and 10 women = blue spots) are alive now (June 1, 2014) and 78 victims (yellow and blue spots)  were alive in 1972 (27 years after the war). Most of them were in solid buildings, and six were in crowded streetcars. Many survivors developed serious diseases and four of them are suffering from multiple cancers. Four victims lost their parents and became orphans, and many were discriminated against.
(Research by KAMATA Nanao,
a professor emeritus at the University of Hiroshima
This chart shows where the 78 victims were when the bomb exploded.

Q:What is ABCC?

The ABCC was set up in November 1946 by the U.S. National Academy of Science to conduct investigations into the effects of radiation among hibakusha in Hiroshima and Nagasaki, and from March 1947, it opened an office within the Red Cross Hospital in Hiroshima. Initially it was funded solely by the Atomic Energy Commission, but later the U.S. Public Health Department, the National Cancer Research Institute as well as the National Heart, Lung and Blood Institute co-funded it.
In November 1950, the ABCC research complex, equipped with various types of the most sophisticated medical instruments, was built on top of the hill at Hijiyama, about 2 kilometers from the city center. It was devoted to collecting a wide range of data regarding the effects of radiation on human bodies, but it provided no medical care to hibakusha. The findings of its scientific research and studies were intended to be utilized to estimate the casualties of future nuclear wars. To achieve this goal, the ABCC conducted medical examinations of many hibakusha, who were brought to the attention of the ABCC by local medical doctors and hospitals. It also asked the relatives of the deceased hibakusha to donate their bodies for autopsies. As hibakusha were always suspicious about the purpose of the ABCC’s investigation and did not trust its staff, the ABCC had to lure the people by providing pecuniary benefit.

ABCC visited the schools in Hiroshima City and took many pictures of boys and girs with keloid scars, and examined their sex organs in the office.



ABCC dissected 7,500 dead victims’ bodies and sent their organs to the United States. After being examined, some of them were given to Hiroshima University 28 years later.


In 1975, Japan and the United States agreed to share equally the operation and management of the facility. The commission was reorganized and renamed the Radiation Effects Research Foundation (RERF).

The Atomic Bomb Casualty Commission in retrospect

Q:What is "A Trillion-Dollar Nuclear Weapon Modernization"?


Q:What is "low -yield warhead"?