Why did President Truman drop the bombs?

August marked the 60th anniversary of the dropping of the atomic bombs on Japan, so it seems appropriate to discuss why. Too many people do not understand why and still question the necessity. People forget how determined the Japanese were.

The first bomb was dropped on 6 August on Hiroshima on Japan’s main island of Honshu. The 20-kiloton uranium 235 bomb was delivered in a high air burst 2,000 feet above ground to eliminate fallout. Hiroshima was selected because it was a port of embarkation and a convoy assembly site. It was also the site of an Army headquarters as well as a substantial manufacturing center. The bomb destroyed two-thirds of the city and killed 70,000 to 80,000 people.

On 9 August 1945, we dropped a plutonium bomb on Nagasaki, on the island of Kyushu, the southernmost of the four main islands of Japan. Nagasaki was the oldest open port of Japan, as well as a major shipbuilding center. The second target selection had been Kokura, but due to clouds the crew was unable to find the aiming point and thus dropped the bomb over the alternate site. About 50,000 leaflets had been dropped over these cities, as well as eight others warning occupants to evacuate because of the impending bombing. The airburst killed 35,000 to 40,000 people.

A third bomb was prepared but it was not used.

Public opinion

It is appropriate to ask why President Truman ordered the dropping of the bombs. In 1945, 85% of the people polled agreed with the decision, and only 10% disagreed that it was necessary to bring about the end of the war. If you had asked veterans of the war, I believe it would have been 100% in favor.

If the question were asked today, there would be fewer favorable responses. In 1995, polls showed 59% agreed and 35% disagreed. A greater percentage of elderly people favored the decision, while a greater percentage of younger and lesser-educated people disagreed with the decision, and it was still lower amongst minorities. Few people in this generation realize how serious the need was to end the war and how awful the casualties would have been to both sides had the war continued.


To understand the decision, consider OPERATION DOWNFALL, which once was labeled top secret. Few people are aware of the extensive plans prepared for the invasion of Japan in our final efforts to conclude the war in the Pacific. In the first invasion, codenamed OLYMPIC, U.S. forces were to land on Kyushu on 1 Nov 45. The second invasion, 1 Mar 46, codenamed CORONET was to involve 22 combat divisions against one million defenders on the main island of Honshu.

Many of us, including myself, were servicemen in WWII and would have been directly involved in the invasion of Japan had it not been for the courage and resolve of President Harry Truman in ordering delivery of the two atomic bombs.

Some present day critics say it was not necessary, that Japan already recognized defeat and would have surrendered irrespective. Not so!

By the summer of 1945 it was clear to analysts that Japan was losing the war, but intercepted cables disclosed that Japanese leaders were not considering surrender. There was no serious response to many approaches for a peaceful conclusion.

Much controversy has taken place as to the need for the use of nuclear weapons to end the war against Japan, which ended 2 Sep 45. The mayor of Nagasaki likened the nuclear bombing to the Holocaust. He asserted the act to be one of the two greatest crimes against society in WWII. Those who have studied the situation, including Japanese, say definitely not so! Many Japanese realize that a continuation would have been even more catastrophic.


Senior military leaders of the day were in almost unanimous agreement that an invasion would be necessary to end the war. Those decisions were carefully considered based upon several imperatives:

    • The hard-line rulers of Japan would not recognize defeat nor respond to peace overtures. Their troops would not surrender just by being overwhelmed in battle. The decrypts of intercepted messages disclosed this and the following points.

    • We had learned lessons from the terrible battle of Okinawa that took place 350 miles south of Kyushu. Okinawa was defended by over 100,000 Japanese troops, and further supported by 50,000 home defense forces. Most were killed and few captured, since they fought in Samurai, Knights of Bushido tradition and refused surrender. The Okinawa invasion was comparable in size to the invasion of Normandy — 550,000 U.S. military personnel were involved and sustained more than 68,000 casualties; 34 allied ships were sunk, and 368 were damaged by 3,000 kamikaze planes. The Japanese demonstrated their willingness to fight to the last man. The Navy had more casualties in that campaign than the total sustained in all previous operations in all wars.

    • In the five campaigns proceeding the contemplated invasion of Japan, the Japanese forces demonstrated that they would fight to the death in a savage resistance.

    • Japan was rapidly mobilizing for all-out defense of the home islands. Their never-defeated major army was brought back from Manchuria. The entire populace was being fully mobilized and systematically prepared to fight the invasion.

    • It would have been possible to bomb Japan extensively with conventional explosives and establish a naval blockade. Together, these actions would have choked the enemy to some extent, but that would not have destroyed the armies nor the will of the people to fight with ferocity for their homeland.

    • Had the invasion been initiated as planned against Japan, the resulting catastrophic destruction and enormous loss of life would have destroyed their civilization. The Soviets would probably have occupied the northern half and thus developed a partitioned country as was done in Korea. The Soviets declared war on Japan on 8 August.

    • Orders had been disseminated by the Japanese high command to kill all POWs, some 150,000 in Japan, plus 80,000 in other occupied Asian areas, plus interned civilians of enemy countries — a total of perhaps 450,000 — upon the initiation of an invasion attempt.

Additional evidence

Following the capitulation, captured documents and interviews of key military persons disclosed the elaborate plans that had been made by the Japanese to defend their home islands. They had 2 million regular troops ready and 25 million additional men, women and children mobilized. The awful extent of that preparation was demonstrated in the training of children to carry explosive packs and throw themselves under tanks.

Information developed later resolved that the Japanese were saving most of their aircraft, fuel and pilots in reserve for the final battle in defense of the home islands. Their plan for the defense of Japan, KETSU-GO included many underground hangers and take-off strips for the launching of massive suicide attacks using improved types of kamikaze craft, as well as conventional aircraft so used. The Japanese had accumulated a total of nearly 13,000 planes for the final defense. They were building a more effective model of the German V-1 Buzz-bomb but modified to include a suicide pilot, greatly increasing their chances of striking their target. They had also assembled suicide frogmen, small suicide boats, submarines and other forms of kamikaze deployments.

The KETSU-GO included methodical means calculated capable of destroying 800 Allied ships. Their air force of army and naval fighters were to fight to the death to control the skies over the southernmost of the principal islands, with as many as 5,000 planes at a time (including the kamikazes used in successive waves), which they calculated would be sustained for 10 days. Within their plans the Imperial navy was to have been totally committed. Some destroyers were to be beached at the last minute to create anti-invasion gun platforms. Japan had identified the planned invasion sites.

Japan’s resolve

Japan tested a nuclear device on 9 August on one of their remote islands and planned to use small nuclear warheads installed on kamikaze-directed bombs against invasion troop ships. The Japanese military expected to kill 10,000 troops with each expenditure. Needless to say, the results would have been horrible with much residual contamination.

The Japanese planners were convinced that they could shatter any invasion force so that the demoralized Americans would back off and they would accept a less than unconditional surrender on face-saving terms.

Even if the Allies gained a foothold on Kyushu, the Japanese had plans to mobilize the full population in the fiercest and most fanatical defense that could be conceived. Army officers had organized youngsters (the schools had been closed) into suicide brigades.

The numbers of Japanese land forces facing the planned invasion force were considerably greater than the over half million men planned to constitute our initial commitment. Planners cautioned against mounting an invasion against a larger force of defenders. The number of Japanese troops on Kyushu increased rapidly during the last few months of our invasion planning, as disclosed from intercepted messages and our intelligence gathering. And those defenders would have been hard-core, well-trained troops, many the elite of their army.

The Japanese had a national slogan: one hundred million will die for the Emperor and nation — and few doubted that they were, as a whole, prepared to fight to the death. Twenty-eight million had been enrolled in a National Volunteer Combat Force, some inadequately armed, but fully committed. We would have had to use our entire military strength in defense.

In the initial planning for the invasion it was thought that our casualties would be 150,000, a figure considered tolerable. However, that estimate had to be raised monthly. The final calculation exceeded one million.

Life-saving decision

Clearly, the loss of lives would have been far greater than initial estimates, probably more than twentyfold, had the invasion plans been carried out. The nuclear bombings averted the need for the scheduled invasions, the results of which would have been far worse than contemplated.

Had the invasion gone forward, the sustained fierce battles would have created enormous casualties. Many of our battle-weary divisions were scheduled to rotate directly to the invasion of Japan from German ports. As one of those scheduled to land as an infantry platoon leader, and in all likelihood been killed, I think I can speak for all veterans; I am glad that President Truman interjected. He took note of the planning, carefully considered the problems and exercised his wise decision to end the war forthwith.

It is clear from a study of the intelligence available and the plans our military prepared in light of then-available information of the intent and capabilities of the enemy that the battle that was to ensue would have become the most awful bloodbath in the history of modern warfare. Had the invasion been undertaken, it is estimated that the Japanese military deaths would have exceeded a million, with over 2 million additional casualties, if not more, plus many millions of civilian casualties also.