Why Hiroshima and Nagasaki were chosen

This is a continuation of a series of articles commemorating the 60th anniversary of the end of the war in the Pacific.

Sixth of a seven-part series

The reason for selecting Hiroshima as the first target is presented below as taken from official documents. With the exception of some necessary editing due to space limitations the following has been reproduced in condensed form from the Top Secret “Tactical Mission Report,” Headquarters Twentieth Air Force APO 234. No attempt has been made to correct the typographic errors.

TOP SECRET
1 Reason for Selection of Targets:

(a) 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 eastern 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 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 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.

TOP SECRET

Part I – Psychological Warfare

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

TO JAPANESE PEOPLE:

“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-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.”

EVACUATE YOUR CITIES

William H. Stewart is a military historical cartographer and has mapped many of the World War II Pacific battlefields. He is the author of the books, Saipan In Flames (translated into Japanese) and Ghost Fleet of the Truk Lagoon now in its 6th printing.

Reference sources: Due to space limitations many reference sources have been omitted. This information will be furnished those interested when requested from the author at e-mail: spno@zoomnet.net.