Worst Decision

10

Bombing of Nagasaki

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Introduction

On August 6, 1945, the United States dropped an atomic bomb on Hiroshima, Japan. That first-ever use of an atomic weapon killed an estimated 140,000 people in all, most of whom were civilians. Three days later, the United States dropped an atomic bomb on Nagasaki. Some 40,000 people, again mostly civilians, died instantly. Another 34,000 died agonizing deaths in the weeks that followed. President Harry S. Truman argued that the bombings were necessary to compel Japan’s surrender and to avoid what likely would have been a far deadlier U.S. invasion. Truman’s decisions, and particularly the decision to bomb Nagasaki, remain hotly debated. The attacks subjected civilian populations to horrific devastation with long-lasting effects. The bombing of Nagasaki was launched two days earlier than planned to avoid bad weather, leaving the Japanese government less time to assess what had happened to Hiroshima and possibly quit fighting. Truman’s private comments suggest that his decision to bomb Nagasaki went beyond forcing Japan’s surrender to include intimidating the Soviet Union. SHAFR historians ranked the bombing of Nagasaki as the tenth-worst decision in U.S. foreign policy history.

The Manhattan Project

The 1938 discovery of nuclear fission by German scientists opened the door to the atomic age. On August 2, 1939, Albert Einstein wrote to President Franklin D. Roosevelt to warn that it was now possible to create “extremely powerful bombs of a new type.” The letter, drafted by Einstein’s fellow physicist Leo Szilard, urged Roosevelt to direct the U.S. government to invest in nuclear physics research and warned that Nazi Germany was already acquiring the uranium needed to build an atomic bomb.

Roosevelt initially dismissed the idea that government action was needed. He quickly changed his mind, however, and directed his administration to explore Einstein’s warning. That work validated the potential for an atomic bomb. In October 1941, two months before Pearl Harbor, Roosevelt approved the start of a U.S. atomic program, dubbed the Manhattan Project because its headquarters were initially in the New York City borough of Manhattan. Roosevelt was determined that the United States would develop the new so-called superweapon before Germany could.

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Albert Einstein's letter to President Franklin D. Roosevelt, August 2, 1939. Franklin D. Roosevelt Presidential Library and Museum.

The hundred-foot steel tower that held the Trinity Test device. Courtesy of the National Nuclear Security Administration.

The hundred-foot steel tower that held the Trinity Test device. Courtesy of the National Nuclear Security Administration.

The Trinity Test

Germany never developed an atomic weapon. U.S. and British scientists, however, did. On July 16, 1945, two months after the end of the war in Europe, the Trinity Test detonated the world’s first atomic device outside Alamogordo, New Mexico. The question for the United States became whether to use the “A-bomb,” as it was dubbed, against Japan.

FDR died three months before the Trinity Test. He left behind no clear plans for how the United States should use an atomic bomb. In September 1944, he and British Prime Minister Winston Churchill had discussed using the weapon against the Japanese, “who should be warned that this bombardment will be repeated until they surrender.” FDR also spoke to aides about ordering a demonstration test to show the Japanese government the destruction that it faced. He told other advisors that he would use the atomic bomb against Germany if it were ready in time. With FDR having failed to establish the rules that would guide the use of the A-bomb, the decision fell to Truman. He only learned about the Manhattan Project after he was sworn in as president on April 12, 1945.

The War in the Pacific

By mid-July 1945, Japan was headed for defeat. U.S. forces had taken the Japanese islands of Iwo Jima and Okinawa, though only after bitter fighting that came at horrific cost to both sides. U.S. bombers were dropping conventional bombs on Japanese cities; the firebombing of Tokyo in March 1945 killed one hundred thousand people. At the Potsdam Conference in July 1945, Joseph Stalin reaffirmed to Truman that the Soviet Union would enter the war in the Pacific, which it did on August 8. Despite the long odds it faced, the Japanese government rejected the Allied demand at Potsdam for an unconditional surrender.

With Japan determined to continue fighting, Truman considered ordering U.S. forces to invade the Japanese main islands. To that end, the Pentagon drafted Operation Downfall. It envisioned a multi-month operation against Japan’s main islands. Based on the bitter resistance U.S. forces encountered at Iwo Jima and Okinawa, planners estimated that the death toll from Operation Downfall would range from several hundred thousand to a million on the Allied side and well into the millions for Japanese soldiers and civilians.

A Marine of the 1st Marine Division draws a bead on a Japanese sniper with his tommy-gun as his companion ducks for cover. The division is working to take Wana Ridge before the town of Shuri. Okinawa, 1945.

U.S. Marines of the 1st Marine Division fighting in Okinawa, June 22, 1945. Courtesy of the National Archives and Records Administration/S.Sgt. Walter F. Kleine.

Truman’s Options

The Trinity Test expanded Truman’s options for forcing Japan’s surrender beyond continued conventional bombing attacks on Japanese cities, launching the large-scale invasion contemplated by Operation Downfall, or retreating from his demand for Japan’s unconditional surrender. He could use the small stockpile of atomic bombs against Japanese cities, or he could order a demonstration test designed to intimidate Japanese officials into surrendering.

Some Manhattan Project scientists argued against using their creation against Japan. They warned in what became known as the Franck Report that “the release of this new means of indiscriminate destruction upon mankind” would “precipitate the race of armaments, and prejudice the possibility of reaching an international agreement on the future control of such weapons.” However, in June, a separate government advisory committee had recommended that the atomic bomb “should be used against Japan as soon as possible; that it be used on a war plant surrounded by workers’ homes; and that it be used without prior warning.”

Truman Decides

Truman accepted the recommendation to use what he called in his diary “the most terrible thing ever discovered.” He later said he made the decision to avoid “an Okinawa from one end of Japan to another.” He rejected a demonstration test as unworkable. The United States had only two working weapons. The test might be a dud and encourage the Japanese to fight on. Japan might shoot down the U.S. bomber if it knew its intended target. Japan might use the time given it to assess the demonstration to dig in against a U.S. invasion.

Truman also doubted that continued conventional bombing raids would force Japan to surrender, given that months of bombings had not broken its will to fight. And abandoning the call for Japan’s unconditional surrender was a nonstarter, given the burning anger in the United States over Japan’s surprise attack on Pearl Harbor and well-documented Japanese war atrocities. Truman reflected the views of many Americans when he responded to a critic of his decisions to bomb Hiroshima and Nagasaki by writing, “When you have to deal with a beast you have to treat him as a beast.” Some of Truman’s private comments also suggest that he wanted to win the war before the Soviet Union could increase its foothold in Northeast Asia.

Portait of President Truman, Harry S. Truman Library

President Harry S. Truman, November 1945. Courtesy of the Harry S. Truman Library.

The Bombing of Nagasaki

Japan did not surrender immediately in the face of Hiroshima’s destruction, so the U.S. plan for a second attack proceeded. The plan had been to launch the attack on August 11. Truman and his advisors saw two bombings in less than a week as the likeliest way to compel Japan’s surrender. However, weather forecasts showed storms hitting Japan by August 11. The mission was moved up to August 9.

A specially equipped B-29 bomber named Bockscar departed from Tinian in the Northern Mariana Islands early on August 9. The crew had nicknamed its cargo, a bomb of a different design than the one dropped on Hiroshima, “Fat Man.” The crew’s orders were to target Kokura, a city of 130,000 that was home to one of Japan’s largest weapons factories. U.S. bombers had yet to hit Kokura, meaning that the United States could measure Fat Man’s full destructive power.

When Bockscar reached Kokura, clouds and smoke obscured the target, the city’s weapons factory. On the plane’s third bombing run, it began to attract heavy antiaircraft fire. Following a pre-established procedure, the B-29 redirected to its secondary target, Nagasaki, a port city with a population of more than 250,000 people. The clouds over Nagasaki broke just as Bockscar arrived. The plane dropped its cargo at 11:01 a.m. local time. Fat Man fell for 47 seconds and then exploded at a height of 1,650 feet.

Nagasaki Atomic Bomb, National Archives

Nagasaki Atomic Bomb Blast. Courtesy of the National Archives and Records Administration/Joe Kosstatscher.

Japan’s Surrender

The bombing of Nagasaki came a day after the Soviet Union declared war on Japan, dashing the hopes some Japanese leaders had that Stalin might act as a neutral arbitrator and prevent further U.S. attacks. Japan’s Imperial Council met on the night of August 9 and debated into the next day. A vote on whether to surrender produced a tie. Emperor Hirohito broke the tie in favor of surrender.

The Japanese government communicated its surrender to the United States and its allies on August 10. The surrender came with one condition, that the emperor be allowed to remain as Japan’s ceremonial head of state. Several days of negotiations on the details followed. As the talks proceeded, the U.S. military worked to construct a third atomic bomb. However, Truman paused that effort while negotiations continued. On August 15, Emperor Hirohito went on national radio to announce Japan’s surrender. It was the first time that most Japanese heard his voice.

Signing the Instrument of Surrender, September 2, 1945. (National Archives Identifier 23658002)

Japanese Foreign Minister Mamoru Shigemitsu signing the Instrument of Surrender on the deck of the USS Missouri, September 2, 1945. Courtesy of the National Archives and Records Administration.

The Legacy of the Nagasaki Bombing

The question that hangs over the bombing of Nagasaki is whether it was necessary. Was three days sufficient time for Japan to absorb the enormity of what happened in Hiroshima? Could the United States have done more to persuade Japan that it would face additional atomic bomb attacks? Was the Soviet entry into the war sufficient by itself to convince Japanese leaders to offer to surrender on August 10? By deciding that the two atomic bombs would come in short order and by speeding up what became the attack on Nagasaki, the United States ensured that those questions will remain forever unanswered.

I think it was necessary to drop one, but the second one could have easily been avoided. I think Japan would have capitulated anyway.

Hans Bethe, a physicist on the Manhattan Project

What Historians Say

  • Kimber Quinney

    Kimber Quinney

    The intention of the bombing of Nagasaki was to kill as many civilians as possible. The dropping of the bomb on Hiroshima can perhaps be justified as necessary to end the war, but the use of the bomb on Nagasaki was an unforgivable gesture of strength vis-a-vis the USSR and served to undermine global stability in the long run.
    Professor of History, California State University San Marcos
  • John Van Sant

    John Van Sant

    While there is justifiable debate about the atomic bombing of Hiroshima to end World War II in the Pacific, the atomic bombing of Nagasaki (which killed 100,000 people, mostly civilians) was completely unnecessary and not justifiable.
    Associate Professor of History and Director of History Graduate Programs, University of Alabama at Birmingham

National Security Archive, GWU

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