About Micronesia

History of Saipan & Micronesia (7)

By William H. Stewart
Military Historical Cartographer


Extraction of a Top Secret Report 

Reason for Selection of Targets:

A. Hiroshima

Hiroshima is highly important as an industrial target. Prior to this attack, Hiroshima ranked as the largest city in the Japanese homeland (except Kyoto) which remained undamaged by the B-29 incendiary strikes. The city had a population of 344,000 in 1940. Hiroshima is an army city - headquarters of the 5th Division and a primary port of embarkation. The entire northeastern and astern sides of the city are military zones. Prominent in the north central part of the city are the Army Division Headquarters marked by the Hiroshima Castle, numerous barracks, administration buildings and ordnance storage houses. The fact that Hiroshima was undamaged made it an ideal target. This was deemed necessary to assess correctly the damage which could be inflicted by the Atomic Bomb. 

The size of the city was another important factor in the selection. According to preliminary data, it was believed that the radius of damage which could be inflicted by the Atomic Bomb was 7,500 feet. By placing the aiming point in the center of the city, the circle of prospective damage covered almost the entire area of Hiroshima with the exception of the dock area to the south.


B. Kokura & Nagasaki

Kokura and Nagasaki contained essentially the same characteristics for a good target as Hiroshima, with the exception that they both had prisoner of war camps nearby. Nagasaki was the poorest of the three targets as to situation and overall construction and for those reasons was made the tertiary target. Nagasaki, one of Japan's leading shipbuilding and repair centers, is also important for its production of naval ordnance and its function as a major military port. 

Another factor which entered into the selection of Nagasaki as a target was the fact that it was virtually untouched by previous bombings, thus enabling an accurate assessment. The size of the city made it ideal for an Atomic Bomb attack. The city is the third largest on the island of Kyushu, with a population of 253,000 persons. The city measures approximately 5 miles from north to south and 5 miles from east to west and it was believed that an accurate drop would destroy the bulk of the city east of the harbor and possibly carry across to the western shore. 

Psychological Warfare: 

On 7 August the Cincpac Advance Psychological Warfare Section was asked to institute a psychological warfare campaign with the Atomic Bomb as its focal point. The plan was drawn up to drop 3,600,000 leaflets daily for 9 days on Japanese cities having a population of more than 100,000 persons. A recording of the leaflet text in Japanese was made by a prisoner of war and broadcast on the Office of War Information radio station to Japan starting at 1830 on 8 August. These broadcasts continued half hourly until the evening of 10 August. The first delivery of leaflet bombs was to be made on 9 August. The plan called for daily delivery for 9 days of 75 M-16 bomb cases, each containing 32,000 leaflets. On the night of 10 August the Japanese government first expressed its willingness to discuss peace negotiations and the Atomic Bomb leaflet program was discontinued.

A copy of the leaflets dropped on Japanese cities in conjunction with the Atomic Bomb together with the English translation follows.


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 2,000 of our giant B-29's 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. Other-wise, we shall resolutely employ this bomb and all our other superior weapons to promptly and forcefully end the war.


Because of the almost inconceivable expense of each individual Atomic Bomb, it is obvious that no live, i. e., "bomb smashing" munitions could be used for practice or training. One of the initial problems of the tactical application of the Atomic Bomb was the necessity for using an air burst to derive the most advantage from the terrific blast effect of the bomb. To get the greatest possible accuracy (using visual instead of radar bombing) with such an expensive weapon it would be necessary to accomplish daylight visual attacks. Because of the wide destructive area of the bomb it would be necessary for only a single bomb to be dropped during any one attack on any one target.


Important cities which had not been previously damaged by demolition or incendiary raids were desirable as initial targets for the Atomic Bomb for two reasons:
  1. The assessment of of the Atomic Bomb damage would not be confused by having to eliminate previous incendiary or high explosive damage.
  2. The Atomic Bomb could be used most economically, i. e., it would destroy all targets within a large area and that it would be more worthwhile to employ it against new areas. 

The four cities of Kyoto, Kokura, Hiroshima and Nigata fulfilled these requirements and were originally assigned to the Atomic Bomb project. This greatly limited target selection for the 509th Group because of the increasing scarcity of individually important targets in the Empire. By mid-July the Bombardment Wings had inflicted widespread damage throughout Japan. The more lucrative targets from the city of Sendai in northern Honshu down to Chirau in southern Kyushu had been struck. 

Another limiting factor was that other combat forces had moved within range of the Japanese homeland - i. e., naval aircraft carrier task forces, the Far Eastern Air Force - and the resulting allocation of targets cut appreciably the Twentieth Air Force's formerly almost unrestricted choice. After a block of targets had been selected, the choice of the particular targets to be attacked on any one day was to be determined by weather conditions and the availability of previous damage assessment. 

A debate broke out among U.S. military planners over whether Japan should be defeated by attrition or direct attack. General MacArthur and Admiral Nimitz favored a direct assault. The Joint Chiefs of Staff scheduled an invasion of Kyushu for October 1, 1945. It was estimated that 1,500,000 troops, 36 divisions would be required with full knowledge that causalities would be heavy. 

By the time the war ended, fragments of the Japanese Army were scattered and marooned on dozens of islands throughout the Pacific and the Imperial Navy was at the bottom of the sea. As Admiral Toyoda remarked, " I do not believe it would be accurate to look upon the atomic bomb and the entry of Soviet Russia as direct causes of the termination of the war. But I do think those two factors did enable us to bring the war to an end without creating utter chaos in Japan". The country was already in a chaotic state, the military was impotent, the economy was wrecked and financially bankrupt. Starvation, death and tragedy was everywhere in Japan. As Theodore Roscoe wrote in his U. S. Naval Institute book,Submarine Operations, "The holocaustal incandescence which consumed Hiroshima and Nagasaki could not blind observers to the fact that the maritime Empire was already destroyed. And long before the first mass air-raids smote Tokyo, many Japanese-held harbors in the Southwest Pacific were as deserted as the bays of the moon, and in many of Japan's home seaports there were vacant docks with rusting bollards where only spiders tied their lines. 

The atomic bomb was the funeral pyre of an enemy who had drowned". It was finally over, more than a thousands days of war had ended and the occupation of Japan began. 

Conclusion of sinking the USS Indianapolis

Captain Hashimoto was ordered to the United States after the war to testify at Captain McVay's Court Martial. McVay was accused of failing to zigzag during war-time conditions and for failure to issue the abandon ship command in a timely manner. Captain Hashimoto was flown to the United States and on December 13, 1945 testified as to the events surrounding the sinking of the Indianapolis. He later described his visit to the United States as "pleasant". Soon after the end of the war he became a Shinto Priest. Captain McVay was later vindicated from any blame concerned with the loss of his ship. All personnel involved in the failure to report the ship's absence from Leyte were also exonerated. On November 6, 1968 in Litchfield, Connecticut, McVay committed suicide, he was found with a pistol in one hand and a toy sailor attached to a key ring in the other. The account of the sinking of the Indianapolis recorded in the "Dictionary Of American Naval Fighting Ships", Volume III, 1968 published by the Navy Department indicates the ship was hit by two torpedoes, this conflicts with Captain Hashimoto's testimony at the Naval Court Of Inquiry where he stated he saw three hits and heard four explosions.


In July 1947 the area was recognized as a Trust Territory by the United Nations. The United States Navy , and later the Department of Interior, became the administrator under a Trusteeship Agreement with the United Nations Organization, the successor to the League of Nations. In 1952, upon signing the Treaty of Peace in San Francisco, Japan legally gave up all claims in the mandated islands formerly provided by the League of Nations and acknowledged the United Nations Agreement establishing the Trust Territory of the Pacific Islands with the United States as the administering authority.
In January 1978 the Northern Marianas became self-governing in political union with the United States under the terms of a Covenant negotiated between the two governments and the area's first elected governor took office. For the first time after more than 300 years under the flags of Spain, Germany, Japan, and the United Nations, the new Commonwealth of the Northern Mariana Islands began to control its a measure of its own destiny. On May 28,1986 the United Nations Trusteeship Council concluded that the United States had satisfactorily discharged its obligations to the islands. On November 4, 1986 United States citizenship was conferred upon those people of the Northern Marianas that met the necessary qualifications. On December 22,1990 the Security Council of the United Nations voted to dissolve the Trusteeship.

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