The Decision That Launched the Enola Gay

April 1, 1994
As Vice President, Harry Truman had not known about the development of the atomic bomb. On the day he assumed the presidency at the death of Franklin D. Roosevelt, Secretary of War Henry L. Stimson had spoken to him briefly and told him that the United States was working on a weapon of extraordinary power. Twelve days later, on April 25, 1945, Stimson and Maj. Gen. Leslie R. Groves, director of the Manhattan Project, briefed President Truman in detail on the secret of the atomic bomb.

The bomb had not yet been tested. Once it was proved to work, Truman would consult with allies and advisors, but the decision on whether to use it would be his. Truman said later that he had no great difficulty in reaching the decision. The question before him was how to end the war and save lives. He regarded the atomic bomb as a weapon — an awe-some one, to be sure — but still a weapon to be used. On Truman’s orders, the B-29 Enola Gay dropped the first atomic bomb on Hiroshima August 6. Another B-29, Bockscar, dropped the second bomb on Nagasaki August 9.

The unconditional surrender of Japan followed on August 15. For the next fifty years, however, Truman’s decision to use the atomic bomb would be questioned again and again, and the retroactive judgment would often be harsh. To understand the decision, it is necessary to examine the circumstances and the options as Truman saw them in the summer of 1945.

World War II would eventually cost the United States more than a million casualties. It consumed the nation’s energies and resources to an extent never experienced before or since. When Truman became President in April 1945, US casualties were averaging more than 900 a day. In the Pacific, the toll from each successive battle rose higher.

The war ended in Europe on V-E Day, May 9, but Japan fought on. The eventual military outcome of the Pacific war had been effectively sealed since the US took the Marianas in 1944, but the Japanese refused to accept defeat.

In 1945, the war had finally come home to Japan. B-29s from Guam, Saipan, and Tinian were striking the Japanese homeland regularly, systematically destroying the industrial cities on Honshu and Kyushu. The US Navy and the Army Air Forces had cut off Japan’s supply lines. Nevertheless, the war threatened to drag on into 1946. US and Allied forces prepared for a difficult and costly invasion of the Japanese islands.

Bushido and Kamikaze

As Japan’s desperation worsened, the ferocity of the fighting intensified. The code of bushido — “the way of the warrior” — was deeply ingrained. Surrender was dishonorable. Defeated Japanese leaders preferred to take their own lives in the painful samurai ritual of seppuku (called hara kiri in the West. Warriors who surrendered were not deemed worthy of regard or respect. This explains, in part, the Japanese mistreatment, torture, and summary execution of POWs). There was no shortage of volunteers for kamikaze missions or of troops willing to serve as human torpedoes or to ride to honorable death on piloted buzz bombs.

Japan was dead on its feet in every way but one: The Japanese still had the means — and the determination — to make the invading Allied forces pay a terrible price for the final victory. Since the summer of 1944, the armed forces had been drawing units back to Japan in anticipation of a final stand there.

The Japanese were prepared to absorb massive casualties. According to Gen. Korechika Anami, the War Minister, the military could commit 2.3 million troops. Commanders were authorized to call up four million civil servants to augment the troops. The Japanese Cabinet extended the draft to cover most civilians (men from ages fifteen to sixty and women from seventeen to forty-five).

The defending force would have upwards of 10,000 aircraft, most of them kamikaze. Suicide boats and human torpedoes would defend the beaches. The Japanese Army planned to attack the Allied landing force with a three-to-one advantage in manpower. If that failed, the militia and the people of Japan were expected to carry on the fight. Civilians were being taught to strap explosives to their bodies and throw themselves under advancing tanks. Construction battalions had fortified the shorelines of Kyushu and Honshu with tunnels, bunkers, and barbed wire.

As late as August 1945, the Japanese Army thought it could destroy most of the invading force and that there was a fair chance the invasion could be defeated.

Invasion Plan and Casualty Estimates

US military opinion was divided on what it would require to induce Japan’s surrender and finally bring the war to an end. Gen. George C. Marshall, Army Chief of Staff, and Gen. Douglas MacArthur, commanding US forces in the western Pacific, believed an invasion of the Japanese home islands would be necessary.

Gen. H. H. Arnold, commander of the Army Air Forces, and Maj. Gen. Curtis E. LeMay (whose XXI Bomber Command in the Marianas was pounding Japan relentlessly) believed that B-29 conventional bombing could do the job. Adm. William D. Leahy, the President’s Chief of Staff, and Adm. Ernest J. King, Chief of Naval Operations, were not fully in accord with Marshall and MacArthur, either.

Truman was aware of the differences among the military leaders but was satisfied that they had been reconciled with Marshall. Furthermore, Truman respected Marshall deeply and regarded him as the nation’s chief strategist, so Marshall’s opinion carried particular weight.

The plan called for an invasion in two stages. Operation Olympic, a land invasion of Kyushu, southernmost of the Japanese main islands, was to begin November 1, 1945. Operation Coronet, planned for March 1, 1946, would be an invasion of Honshu, the largest island. The Joint Chiefs expected the two-stage invasion to involve some five million troops, most of them American. The invasion was to be preceded by a massive aerial bombardment, reaching maximum intensity before troops went ashore on Honshu.

Casualty estimates varied. Military planners figured the invasion of Kyushu alone would take between 31,000 and 50,000 US casualties in the first thirty days and that the combined US losses from Operations Coronet and Olympic would exceed 500,000. President Truman believed that, unless he used the atomic bomb, an invasion was necessary and that the casualties would be enormous.

Strategic Bombing

The capture of the Marianas in the summer of 1944 had given the AAF bases 1,300 miles from Tokyo. B-29s from Guam, Saipan, and Tinian could reach all the major cities in Japan, including the big industrial cities on Honshu. B-29s operated at altitudes too high for Japanese fighters to stop them.

In January 1945, General LeMay took over XXI Bomber Command. On the night of March 9-10, he launched a massive mission — 334 B-29s — to drop incendiary bombs on Tokyo. It was the most destructive raid in history. The official casualty report listed 83,793 dead and 40,918 wounded. Sixteen square miles of Tokyo were destroyed that night. In Operation Starvation, conducted concurrently with the bombing campaign, B-29s mined the waters along the Japanese coast, cutting off maritime transportation and the import of food and raw materials.

The long-range B-29, which first struck Japan in June 1944 from bases in China, inspired fear and awe. The Japanese called it “B-san,” or “Mr. B.” General Arnold, on a visit to Guam in June 1945, expressed his belief that the B-29 campaign “would enable our infantrymen to walk ashore on Japan with their rifles slung.”

The B-29s systematically laid waste to Japan’s large industrial cities. LeMay told Arnold there would soon be nothing left to bomb or burn, except for Kyoto (the old capital) and four other cities — Hiroshima, Nagasaki, Niigata, and Kokura — that were barred for routine B-29 missions. These four were, of course, on the target list for the “special bomb.”

The Emperor Takes a Hand

By the summer of 1945, the Japanese government had split into a peace faction (including Prime Minister Kantaro Suzuki) and a war faction (General Anami and the military). The war faction was powerful, but the peace faction was gaining an extraordinary ally: the Emperor, Hirohito. Regarded as divine and the embodiment of the Japanese state, the Emporer supposedly “lived beyond the clouds,” above politics and government. In fact, he was interested and well informed. While he did not interfere, he was often present at important meetings.

The B-29 missions strengthened Hirohito’s growing belief that Japan should not be devastated further in a losing cause. On March 18, he toured areas of Tokyo that had been firebombed March 9-10. The experience persuaded him that the war must end as quickly as possible.

Hirohito shattered precedent at a meeting of the Supreme War Council June 22, openly stating his criticism of the military: “We have heard enough of this determination of yours to fight to the last soldiers. We wish that you, leaders of Japan, will now strive to study the ways and means to conclude the war. In so doing, try not to be bound by the decisions you have made in the past.”

Anami and his faction managed to sidestep the Emperor’s rebuke. All concerned — including the Emperor — hoped that the Soviet Union could be persuaded to act as an intermediary and help end the war on a more acceptable basis than unconditional surrender. The rationale for this, as the Japanese saw it, was that Japan’s neutrality had allowed the Russians to concentrate on their real enemy, the Germans, and that in the postwar world, the Soviet Union would find a strong Japan useful as a buffer between its Asian holdings and the United States.

Through July and into August, Japan continued to hope it could negotiate terms, including concessions for control of the armed forces and the future of its military leaders. The passage of time and the repeated publication of pictures from Hiroshima and Nagasaki have transformed Japan’s image to that of victim in World War II. In the 1940s, Japan’s image was different.

The Allies had imposed unconditional surrender on Germany. The United States was not inclined to make deals with the Japanese regime responsible for Pearl Harbor, the Bataan death march, the forced labor camps, habitual mistreatment of prisoners of war, and a fifteen-year chain of atrocities stretching from Manchuria to the East Indies.


Basically, President Truman and the armed forces had three strategic options for inducing the Japanese surrender:

Continue the firebombing and blockade. After the war, the Strategic Bombing Survey would conclude that without the atomic bomb or invasion, Japan would have accepted unconditional surrender, probably by November and definitely by the end of the year. In 1945, however, the AAF was not able to persuade General Marshall that this strategy would work.

Invasion. Neither Marshall nor Truman was convinced that LeMay’s B-29 bombing campaign could bring a prompt end to the war. In their view, the only conventional alternative was invasion.

Use the atomic bomb. Within a few years after World War II, the specter of global nuclear war (combined with visions of Hiroshima) would imbue the bomb with special horror. In 1945, the perspective was different. Doubts about use of the atomic bomb were mostly of a strategic nature, reflecting the belief that an invasion might not be necessary or that bombing and blockade would be sufficient. (Use of the bomb to end the war eventually saved Japanese casualties, too. The incendiary bombs from B-29s were taking a terrible toll. The attack on Tokyo in March killed more people than either the Hiroshima or Nagasaki bombs.)

Truman was acutely aware that hesitation would be paid for in blood. The Japanese refusal to surrender led to 48,000 American casualties in the battle for Okinawa between April and June. Kamikaze attacks in that battle sank twenty-eight US ships and did severe damage to hundreds more. The Japanese force on Okinawa was only a fraction the size of the one waiting in the home islands.

Advice About the Bomb

As discussions continued, US authorities made preparations for the decision that seemed most likely. In May, a special committee in Washington nominated four urban industrial centers — Kokura, Hiroshima, Niigata, and Kyoto — as targets. Secretary of War Stimson struck Kyoto (Japan’s capital for more than 1,000 years) from the list. The military picked Nagasaki as the fourth potential target.

The Interim Committee on S-1 (a code term for the Manhattan Project) told the President that the bomb should be used against Japan and that a demonstration explosion would not be sufficient. Reasons included the possibility that the bomb might not work, that the Japanese might think the demonstration was faked, and that there was no way to make the demonstration convincing enough to end the war.

Military leaders accompanied the President to the Big Three meeting at Potsdam in July, and discussions continued there. In his memoirs, Truman said that Secretary of State James F. Byrnes, Mr. Stimson, Admiral Leahy, General Marshall, and General Arnold reached a consensus at Potsdam that the bomb should be used. In fact, the advice was not so clear-cut. Although Arnold supported the decision, he repeated his view that use of the bomb was not a military necessity.

Casualties were increasing with every day that Japan refused to surrender. Truman’s biographer, David McCullough, writes, “Had the bomb been ready in March and deployed by Roosevelt, had it shocked Japan into surrender then, it would have already saved nearly fifty thousand American lives lost in the Pacific in the time since, not to say a vastly larger number of Japanese lives.”

During the Potsdam conference, Truman received word that the “Fat Man” bomb had been tested successfully at Alamogordo, N.M., on July 16. On July 25, the War Department relayed Truman’s order that the 509th Composite Group should deliver the first “special bomb” as soon after August 3 as weather permitted on one of the four target cities.

Among those at Potsdam staunchly supporting the decision to use the bomb was British Prime Minister Winston Churchill. Years later, Churchill still believed that Truman’s decision had been right.

The Potsdam Proclamation, issued July 26 by the heads of government of the US, UK, and China, warned of “utter devastation of the Japanese homeland” unless Japan surrendered unconditionally. “We shall brook no delay,” it said. The same day, the cruiser Indianapolis delivered the U-235 core of the “Little Boy” bomb to Tinian.

On July 28, Prime Minister Suzuki declared the Potsdam Proclamation a “thing of no great value” and said “We will simply mokusatsu it.” Literally, mokusatsu means “kill with silence.” Suzuki said later the meaning he intended was “no comment.” The Allies took the statement as rejection of the Potsdam Proclamation.

Hiroshima and Nagasaki

The unit that would deliver the atomic bombs, the 509th Composite Group, had been organized in 1944. Crews were hand-picked by the commander, Col. Paul W. Tibbets, Jr. In the early morning hours of August 6, the Enola Gay, flown by Tibbets, took off from Tinian. The primary target was Hiroshima, the seventh largest city in Japan, an industrial and military shipping center on the Inland seacoast of Honshu. At precisely 8:16 a.m., the atomic bomb fell on Hiroshima. More than half of the city was destroyed in a flash, and about 80,000 people were killed.

Reaction by the Japanese Cabinet was split between the war faction and the peace faction. With the cabinet at an impasse, Hirohito took a more assertive position. On August 8, the Emperor instructed Foreign Minister Shigenori Togo to tell Prime Minister Suzuki that Japan must accept the inevitable and terminate the war with the least possible delay and that the tragedy of Hiroshima must not be repeated.

Anami could not bring himself to flatly defy the Emperor, but he continued to argue his position passionately. Hard-liners in the military were plotting to kill Suzuki and others of the peace faction. Anami was not part of the plot — although his brother-in-law, Masahiko Takeshita, was a ringleader.

The Soviet Union, seeing an opportunity for easy pickings with limited risk, declared war on Japan August 8. Despite the desperation of a war suddenly active on two fronts, the Japanese were not quite ready to capitulate.

The primary target for the second atomic bomb mission on August 9 was Kokura, but the aimpoint was obscured by smoke drifting from a nearby city that had been bombed two days earlier. Bockscar diverted to Nagasaki on the western coast of Kyushu. Nagasaki was heavily industrialized. The Mitsubishi conglomerate operated a shipyard, electric equipment production facilities, steel factories, and an arms plant there. The aimpoint for Bockscar was the Mitsubishi Steel and Arms Works. The bomb exploded on Nagasaki at 11:02 a.m., killing 40,000.

In his radio address August 9, President Truman said the United States had used the atomic bomb “against those who attacked us without warning at Pearl Harbor, against those who have starved and beaten and executed American prisoners of war, against those who have abandoned all pretense of obeying international laws of warfare. We have used it to shorten the agony of war, in order to save the lives of thousands and thousands of young Americans. We shall continue to use it until we completely destroy Japan’s power to make war. Only a Japanese surrender will stop us.”

“Bear the Unbearable”

Japanese deliberation on August 9 lasted all day and into the night. At a cabinet meeting that began at 2:30 p.m. — hours after the second atomic bomb had fallen — Anami said, “We cannot pretend to claim that victory is certain, but it is far too early to say the war is lost. That we will inflict severe losses on the enemy when he invades Japan is certain, and it is by no means impossible that we may be able to reverse the situation in our favor, pulling victory out of defeat.” Finally, at 2:00 a.m. on August 10, the Emperor told the Big Six meeting (the Supreme War Council) that “the time has come to bear the unbearable” and that “I give my sanction to the proposal to accept the Allied Proclamation on the basis outlined by the Foreign Minister.”

At 4:00 a.m., the cabinet adopted a message for radio transmission to Allied powers, saying in part: “The Japanese Government [is] ready to accept the terms enumerated in the joint declaration which was issued at Potsdam on July 26th, 1945, by the heads of the Governments of the United States, Great Britain, and China, and later subscribed to by the Soviet Government, with the understanding that the said declaration does not comprise any demand which prejudices the prerogatives of His Majesty as a Sovereign Ruler.”

The Allied response August 11 said that the “authority of the Emperor and the Japanese Government to rule the state shall be subject to the Supreme Commander of the Allied Powers” and that “the Emperor shall authorize and ensure the signature by the Government of Japan and the Japanese General Headquarters of the surrender terms.”

V-J Day

The Anami faction continued to haggle, but at noon on August 14, the Emperor asked the cabinet to prepare an Imperial Rescript of Surrender. He said that “a peaceful end to the war is preferable to seeing Japan annihilated.” The plotters engaged in various disruptive actions in the hours that followed, but it was over. At 11:30 p.m. the Emperor recorded his radio message for broadcast the following day. General Anami, preferring to die rather than see Japan surrender, committed seppuku at 5:00 a.m., August 15.

In the Imperial Rescript of Surrender, broadcast at noon on August 15, Emperor Hirohito said, “Despite the best that has been done by everyone — the gallant fighting of the military and naval forces, the diligence and assiduity of Our servants of the State, and the devoted service of Our one hundred million people — the war situation has developed not necessarily to Japan’s advantage, while the general trends of the world have all turned against her interest.

“Moreover, the enemy has begun to employ a new and most cruel bomb, the power of which to do damage is, indeed, incalculable, taking the toll of many innocent lives. Should We continue to fight, not only would it result in an ultimate collapse and obliteration of the Japanese nation, but also it would lead to the total extinction of human civilization. [Emphasis added.]

“Such being the case, how are We to save the millions of Our subjects, or to atone Ourselves before the hallowed spirits of Our Imperial Ancestors? This is the reason why We have ordered the acceptance of the provisions of the Joint Declaration of the Powers.”

V-J Day was celebrated August 15. General MacArthur accepted Japan’s formal surrender September 2 on the battleship Missouri in Tokyo Bay. The atomic bomb did not win the war. Japan had been defeated already by the land, sea, and air campaign that went before. It is reasonable to conclude, however, that the bomb did force the Japanese surrender — and considerably sooner than it would have occurred otherwise.