In August 1945, the U.S. military dropped two atomic bombs on Hiroshima and Nagasaki. From the outside, Japan seemed to be ignorant of the arrival of atomic bombs. In fact, before the first atomic bomb was dropped, the US military dropped a large number of leaflets marking some Japanese cities to warn Japanese citizens to leave. The content is roughly: "Please read carefully, these will be related to the lives of you and your relatives and friends. In the next few days, some cities indicated on the back of the flyer will be bombed by air raids. These cities have military installations or arsenals. We They must be destroyed so that the war will end as soon as possible. The bombs do not grow eyes and may harm innocent people. So, I warn you, immediately evacuate these marked cities..." Many people think that the flyer does not specify that the US military will use atomic bombs. The Japanese just know It’s not surprising that the U.S. military will conduct air strikes from time to time during the war. Is it true that Japan is completely unaware of the arrival of the atomic bomb?
Flyers dropped by the US army
On April 18, 1942, 16 B-25 Mitchell bombers of the US Army Air Force bombed Tokyo. The Chief of Staff of the Japanese Army, Sugiyama Moto, worried that the United States would launch a larger-scale air strike against Japan in the future, so he hoped to establish an intelligence agency that specializes in collecting US bombers, and this intelligence agency needs to be hidden. In September 1942, the Japanese Army requisitioned a welfare center for the elderly. The center was about 80,000 square meters. Because it was equipped with a hospital and a chapel, the US military did not include it as a target for bombing. The Japanese Army Staff Headquarters sent the "Army Central Communications Research Institute" to the welfare center. And this external name is just a cover. Actually here is the "Special Intelligence Department of the Japanese Army Staff Headquarters", which is a confidential department whose main task is to collect and intercept radio information from the US Air Force and to decrypt the intercepted information. Targeted surveillance of U.S. bombers. As the war became increasingly anxious, the number of the "Special Intelligence Department" reached nearly 200.
Beginning in March 1945, the US military used B-29 bombers to bomb various parts of Japan. The "Special Intelligence Department" stepped up its efforts to intercept and decrypt the communication signals of the B-29 bombers in order to defend the Japanese mainland. Through the analysis of the B-29 call signs, the "Special Intelligence Department" has grasped the call signs of the B-29 bombers on multiple islands of the US military, and thus can grasp how many B-29 bombers are dispatched from which island. In June, the new 600 series callsigns appeared on Tianning Island. Originally, Tianning Island used the 700 series callsigns, but the newly deployed 10 B-29 bombers used the 600 series callsigns, which aroused the vigilance of the Japanese army. And it was this mysterious force that dropped atomic bombs on Hiroshima and Nagasaki in the future.
B-29 bomber
At 3 o'clock in the morning on August 6, 1945, when the B-29 bomber took off from Tinian Island, the "Special Intelligence Department" had intercepted the communication signal and recorded encrypted telegrams for deciphering. Five hours before the B-29 bomber dropped the atomic bomb on Hiroshima, the "Special Intelligence Service" deciphered the code, analyzed information from Washington, and combined news from Melbourne and Sydney. At that time, it was determined that B-29 was carrying an atomic bomb. Hideki Tojo, who took over as Chief of Staff of the Japanese Army in 1944, said that the United States is the fastest-growing country in the research and manufacture of atomic bombs, and it will control the death toll in the war. On August 8th after the atomic bomb exploded in Hiroshima, the "Special Intelligence Department" held an internal commendation meeting. The then Chief of Staff of the Army, Umezu Mijiro, admitted that before the B-29 dropped the atomic bomb, the "Special Intelligence Department" had known intelligence analysis. B-29 was loaded with an atomic bomb. But why it was not intercepted or issued an alert was not mentioned, and said that the B-29 must be shot down next time.
In the early morning of August 9, the "Special Intelligence Department" intercepted the communication of the 600 series call sign again. There is no doubt that an atomic bomb will be dropped somewhere in Japan in a few hours. Five hours before the atomic bomb was dropped on Nagasaki, Umezu Mijiro received the report and fully grasped the situation. At that time, Omura, Kyushu, Japan deployed combat troops to intercept. But until B-29 entered Kyushu at 9 a.m., it would go to Ogura. Omura’s troops did not receive any orders to intercept them. Ogura’s visibility was poor and flew to Nagasaki. At 11:02 am, the atomic bomb was dropped on Nagasaki. Nagasaki did not receive any warnings or evacuation orders.
Nagasaki
after the atomic bomb explosion On August 11, it was learned that Japan had accepted the "Potsdam Declaration." Held by the "Special Intelligence Department"The materials are top secret. Therefore, the Chief of Staff Umezu Meijiro decided to destroy all the confidential documents previously collected, intercepted, and managed. Therefore, only the personnel involved in and in charge of the "Special Intelligence Department" knew in advance that the US military B-29 carried an atomic bomb to bomb Japan. The top Japanese level and the military didn't know it from beginning to end. Many years later, with the disclosure of the staff of the "Special Intelligence Department" and the report of Japan's NHK TV station, the Japanese people only learned this shocking secret. Why conceal it seems to be a mystery. Dear friends, what do you think is the reason?
