by Steve Olson
On March 10, the reactors at Hanford suddenly shut down when the electrical system went out. A balloon bomb from Japan had become entangled in high-voltage electric lines near the site and had burst into flames. Safety systems prevented the reactors from overheating, and they were quickly restarted. As the “Unusual Incident” report stated, “The line was not seriously damaged as evidenced by the fact that it was restored to service in two minutes.”
The US military had asked newspapers not to report on the fire balloons so that the Japanese would not know that their bombs were reaching the United States, which might cause them to launch more. But very few of the balloons caused any damage. The jet stream blows strongly enough for the balloons to reach America only in the winter, when American forests are cold, wet, and unlikely to ignite from a firebomb. By the spring of 1945, the Japanese had given up on the campaign.
On May 5, 1945, minister Archie Mitchell from Bly, Oregon, and his pregnant wife Elsie took five Sunday school children on a picnic in the woods near their town. While the minister was unloading the car, his wife and the children went to investigate a mysterious object they had found nearby. When they moved it, the balloon bomb exploded, and all six were killed. Today, a monument at the site, erected by the Weyerhaeuser Company, reads, “Only Place on the American Continent Where Death Resulted from Enemy Action During WW II.”
Chapter 14
TRINITY
IN THE LAST FEW DAYS OF JUNE 1945, METALLURGIST CYRIL SMITH and his colleagues in the Chemistry and Metallurgy Division at Los Alamos extracted from a hot-press mold two solid hemispheres of plutonium. Combined, they were about the size of an apple—a bit more than three-and-a-half inches across. They would fit “rather easily, and even rather pleasantly, in the hand,” Smith later recounted, though they were incongruously heavy—about the weight of a bowling ball. Pure plutonium metal has a steel-gray color when it is cast, but it tarnishes quickly in air. To keep that from happening, and to avoid contaminating anyone who handled the hemispheres, the metallurgists had plated the plutonium with a layer of nickel. But the flat surface of one of the hemispheres had blistered, which was a potential disaster. Any imperfection in the surface could cause asymmetries during implosion, which might cause the bomb to fail. Smith’s team came up with a solution. They placed a layer of gold foil between the two hemispheres, which they hoped would render the compression uniform. “My fingers were the last to touch those portentous bits of warm metal,” Smith recalled many years later. “The feeling remains with me to this day.”
The other pieces of the world’s first atomic bomb were coming together at the same time. The best explosive lenses emerging from the candy-making machines were packed into a five-foot sphere of an aluminum-copper alloy known as Duralumin, which had been used in previous decades to make the frames of airships. The detonation system, after a frustrating spring spent trying to get the 32 detonators to fire simultaneously, was finally working, though the director of the test suggested stocking up on rabbits’ feet and four-leaf clovers. The design of the walnut-shaped initiator, which would fit into a hollow in the center of the plutonium and produce neutrons at the height of implosion, was finalized at the end of April, and the first complete one was manufactured in June. A technician accidentally dropped that first initiator and watched with horror as it rolled toward a drainpipe. It stopped just short.
Meanwhile, a new and highly unusual laboratory was taking shape on a barren plain 150 miles south of Los Alamos. The region was known as the Jornada del Muerto—the dead man’s journey—a name given it by conquistadors trudging across the desolate flatlands from New Spain. About two miles from a four-room ranch house appropriated by the army at the beginning of the war, metalworkers erected a surplus Forest Service fire watchtower a hundred feet tall. Ten miles south of the tower, a straggly basecamp housed the 250 or so people working at the site. About six miles north, south, and east of the tower, concrete shelters dug into the earth were filled with electrical equipment, cameras, radiation detectors, and searchlights. When the time came to implode the plutonium in the test device atop the tower, observers in the shelters could measure the bomb’s effects.
Oppenheimer had code-named the test Trinity. He later cited several sources as inspirations for the name, including part of a John Donne poem he admired:
Batter my heart, three person’d God; for, you
As yet but knocke, breathe, shine, and seeke to mend;
That I may rise, and stand, o’erthrow mee, and bend
Your force, to breake, blowe, burn and make me new.
THROUGHOUT THE SPRING, as German opposition collapsed, Groves had been thinking about where to drop atomic bombs on Japan. As the Trinity test approached, the work to identify targets intensified.
Groves had enlisted a committee of assistants, military men, and technical experts from Los Alamos to help him sort through the choices. Known as the Target Committee, the group held its first meeting on April 27 at the Pentagon and began laying out the criteria that potential targets must meet. First, the men dropping the bombs should be able to see the target rather than relying on radar. That way, the likelihood of a direct hit would be substantially increased and observers on nearby planes could document the bombs’ destructiveness. At the committee’s first meeting, this criterion led to an extensive discussion of late-summer weather in Japan, which tends to be cloudy and hot. Only a few days per month were likely to have conditions suitable for visual bombing. Decisions on exactly when and where to drop atomic bombs would therefore have to be left to commanders in the field. Only they would have access to all the information, including weather information, needed to use the bombs effectively.
Second, the bombs should be used in such a way as to have the greatest possible impact on the Japanese psyche. Though Japan was clearly headed toward defeat in the spring of 1945, brutal combat was still under way on Okinawa, and hardliners in the Japanese government vowed that they would keep fighting even if the Americans launched an invasion of the Japanese mainland. Many US military and civilian leaders thought that the Japanese needed to be subjected to some sort of psychological shock to convince them to end the war, and using atomic bombs against Japanese cities seemed perfectly suited to the task. Granted, the cities chosen should have military installations, including either “important headquarters or troop concentrations, or centers of production of military equipment and supplies,” as Groves put it in his memoirs. But most Japanese cities contained such installations. Furthermore, as the Target Committee concluded at its third and final meeting on May 28, the bombing crews should “endeavor to place first gadget in center of selected city” rather than relying on subsequent bombs to finish the job. Small and isolated military targets in remote locations would be hard to hit and would not provide the necessary shock value. Only cities would do.
Third, the targets should be relatively undamaged before the bombing so that the full effects of the bombs could be determined. This was getting increasingly difficult by the summer of 1945. In March, the air forces began bombing Japanese cities from air bases in the recently captured Mariana Islands with the intention, as expressed in the notes of the first Target Committee meeting, “of not leaving one stone lying on another.” Eventually, more than 60 cities in Japan were attacked and hundreds of thousands of civilians were killed, including nearly a hundred thousand people in the March 9–10 firebombing of Tokyo. Groves and Stimson eventually had to plead with the leaders of the air forces to leave a handful of cities untouched.
One city perfectly met all the committee’s criteria, as far as Groves was concerned: Kyoto, the ancient capital of Japan. With a population of about a million, Kyoto was Japan’s fourth largest city. It was also an intellectual and religious center, home to thousands of temples and shrines. Destroying these cultural treasures in a single fearsome blow was just the kind of psychological shock Groves hoped to administer. Moreover, as the Target Committee notes put it, “Kyoto has the advantage of the people being m
ore highly intelligent and hence better able to appreciate the significance of the weapon.” In the list prepared by the Target Committee in May, Kyoto was on top, followed by four more cities: Hiroshima (“an important army depot and port of embarkation in the middle of an urban industrial area”), Yokohama (“an important industrial area which has so far been untouched”), Kokura Arsenal (“one of the largest arsenals in Japan . . . surrounded by urban industrial structures”), and Niigata (“its importance is increasing as other ports are damaged”).
Well before the Target Committee began its work, Groves had become convinced that two atomic bombs would be needed to force Japan to surrender, in part because of a conversation he had had with Navy Rear Admiral William Purnell. The first would show that the United States could build such weapons, Purnell told him. The second would demonstrate that the United States could keep building atomic bombs until the Japanese surrendered.
But of course Groves had another reason for dropping two bombs on Japan. He had spent $2 billion on two different approaches to nuclear weapons: one using uranium from Tennessee, the other using plutonium from Hanford. Dropping two bombs would justify both.
On May 30, two days after the third and final Target Committee meeting, Groves drove across the Potomac River to meet Stimson in the Pentagon. During the meeting, according to Groves’s recollections, Stimson asked whether he had selected the targets to be bombed. Groves replied that a report on potential targets had been completed and that he was planning to bring it to General Marshall the next day. Stimson asked to see it. Groves replied, “It’s across the river and it would take a long time to get it.”
Stimson said, “I have all day and I know how fast your office operates. Here’s a phone on this desk. You pick it up and you call your office and have them bring that report over.” When Groves continued to object that Marshall should see the report first, Stimson replied, “This is one time I’m going to be the final deciding authority. Nobody’s going to tell me what to do on this. On this matter I am the kingpin and you might just as well get that report over here.”
As soon as the report arrived, Stimson read through it. He demanded that Kyoto be removed from the list. He said that it was the cultural center of Japan and he would not see it destroyed. Stimson then rose from his chair, walked to General Marshall’s adjacent office, and asked if he was busy. “Groves has just brought me his report on the proposed targets,” he told Marshall. “I don’t like it. I don’t like the use of Kyoto.”
Opinions differ on exactly why Stimson was so opposed to bombing Kyoto. Stimson had spent several days in Kyoto in 1926 with his wife, and undoubtedly the two of them had visited some of the city’s cultural sites; perhaps he was remembering these places as he read Groves’s target list. Stimson was also the product of an older, Victorian morality. He often lamented the indiscriminate bombing of civilians during World War II, even as he permitted such bombing to continue. Maybe he used the protection of Kyoto as a way to ease his conscience after so many other Japanese cities had been destroyed. Or he might have been thinking about the need to rebuild relations with Japan after the war. As he wrote in his diary about the possibility of bombing Kyoto, “the bitterness which would be caused by such a wanton act might make it impossible during the long post-war period to reconcile the Japanese to us in that area rather than to the Russians.” All these factors could have been at work, but one thing is certain: in demanding that Kyoto be removed from the target list, Stimson prevented an even greater tragedy than the ones that were on the way. With a population of about a million, Kyoto was more than three times the size of Hiroshima and four times the size of Nagasaki. If it had been successfully bombed, the death toll could easily have approached a half million.
For the next two months, Groves tried as many as a dozen times to have Kyoto placed back on the list, but each time Stimson rebuffed him. Finally, Stimson took his case all the way to the president. “As to the matter of the special target [Kyoto] which I had refused to permit,” Stimson wrote Groves in July from the Potsdam Conference in Germany, where Truman, Churchill, and Stalin were negotiating over the future of the postwar world, “he [Truman] strongly confirmed my view and said he felt the same way.”
Nagasaki was a very late addition to the target list. It was among a list of 17 cities cited as potential targets in the Target Committee’s first meeting, but after that it was not mentioned again in the committee’s meeting notes. However, Yokohama had been severely bombed by the air forces and was therefore no longer a good target. Niigata, a port on the west coast of Japan north of Tokyo, had taken the place of Kyoto. That left one open slot on the list of four cities prepared by the Target Committee.
On July 24 a message arrived in Washington, DC, from air forces chief Henry Arnold, who was with the president at the Potsdam Conference in Germany. It said that Nagasaki should be added to the list of target cities. The generals in Washington who received the message were not happy with the choice. Nagasaki did not meet the criteria established by the Target Committee. It nestled within two valleys that would contain and redirect the force of the bomb, making it hard to determine the bomb’s effects. It also had already been bombed several times, though the damage done was relatively minor. And Nagasaki was unusual among Japanese cities, though no one seems to have acknowledged its history when it was being considered as a target. Nagasaki was a major port for Portuguese and Dutch traders after European contact in the 16th century. When Japan closed its border to foreigners in the first half of the 1600s, it allowed Dutch traders to continue to do business on a small island in Nagasaki’s harbor. As a result of this history, Nagasaki remained the most Western of Japanese cities, with a sizable Roman Catholic population and a large cathedral in the city’s Urakami Valley. Even after Japan reopened its borders to foreigners in 1854, Nagasaki remained a center of Western learning.
Cables to Potsdam from the generals in Washington, DC, who objected to Nagasaki failed to alter the decision. By the evening of July 24, Nagasaki was the fourth city on the target list.
A July 25 directive, drafted earlier by Groves and revised once the target list was final, laid out the plan:
1.The 509th Composite Group, Twentieth Air Force, will deliver its first special bomb as soon as weather will permit visual bombing after about 3 August 1945 on one of the targets: Hiroshima, Kokura, Niigata and Nagasaki. . . .
2.Additional bombs will be delivered on the above targets as soon as made ready by the project staff. Further instructions will be issued concerning targets other than those listed above.
This was the only written command ever issued to use atomic bombs on Japan. It was signed not by Truman, who for the most part maintained his distance from decision making about the bombs, but by General Thomas Handy, who was the army’s acting chief of staff in Washington, DC, with Marshall away at the Potsdam Conference. As Groves reflected after the war, President Truman did not have to issue an order to use atomic bombs on Japan. The endgame had been preordained long before, when Roosevelt decided to back the Manhattan Project. Groves was only slightly exaggerating when he said after the war that Truman “was like a boy on a toboggan.” The technological and bureaucratic momentum of the project was immense, and Groves had a powerful self-interest in keeping that momentum going. He had devoted the last three years of his life to this project and was going to see it through. The only thing that could have stopped the use of atomic bombs was a decision by Truman or a group of his top advisors not to use them—and that was not going to happen. Truman and his advisors had already accepted the idea of killing hundreds of thousands of Japanese civilians with firebombs. Meanwhile, they were playing a delicate diplomatic game with Stalin. At the Yalta Conference earlier that year, Stalin had promised to enter the war against Japan three months after Germany was defeated, which meant the Soviets would attack Japan no later than August 8. Now the use of atomic bombs looked like a way of forcing the Japanese to surrender before the Soviet Union entered the war, thereby prev
enting the Soviets from demanding territorial or political concessions afterwards.
On the domestic front, Truman would have been politically crucified if he prolonged the war by refusing to use weapons that had cost $2 billion to build. Furthermore, he never seemed to have fully realized—or refused to fully realize—that the bombs were going to be dropped on cities. He seems to have thought that Hiroshima, at least, was a purely military target, even though a single question to one of his advisors would have revealed otherwise. Only after the event did he acknowledge what the bombs had done.
LEO SZILARD DIDN’T GIVE UP when the Scientific Panel failed to endorse the Franck committee’s call for a demonstration of an atomic bomb. He decided that he would have to act on his own without the other members of the committee.