Now It Can Be Told: The Story of the Manhattan Project

Introduction (Edward Teller)

Edward Teller argues that Groves’s most underappreciated contribution was his practical decisiveness and his choice of Oppenheimer as scientific director, and that the gulf between military and scientific communities—which Groves helped bridge—remains existential for democratic survival.

• Groves was a straightforward, non-devious man whose practical decisiveness—his ability to ignore complexity and arrive at workable results—was his core strength, even when scientists found him insufficiently sophisticated.
  • Vannevar Bush had warned that Groves might lack sufficient tact for the role, a concern Groves himself reported in the book.
  • “We (the military leaders) came up through kindergarten with them (the scientists). When it came to what was so and what was probably so, we knew just about as much as they did.” —Leslie R. Groves
• Groves’s selection of Oppenheimer as scientific director—over security objections—was his most consequential decision, and the contrast and cooperation between the two men is the central human story of the Manhattan Project.
  • Oppenheimer knew the research in every part of the laboratory and understood the human relationships among the more than 10,000 people who worked at Los Alamos.
  • Teller states he knew no laboratory director whose work begins to compare in excellence with Oppenheimer’s.
• Scientists at Los Alamos resented military security restrictions as infantilizing, but Chadwick’s later insistence—revealed to Teller at a 1949 dinner—that the project would have failed without Groves changed Teller’s assessment.
  • Chadwick told Teller most emphatically that the atomic bomb project would never have succeeded without General Groves, and that Groves understood the overriding importance of the project better than some leading American scientists.
  • The context was likely Chadwick’s awareness that the Soviets had just detonated their own atomic bomb, giving new urgency to the question of American resolve.
• The bridge between military and scientific communities that Groves and Oppenheimer constructed during the war must be rebuilt in the postwar era, because national security and technological capability are now inseparable.
  • Teller argues that mutual understanding and significant collaboration between those who defend their nation with their lives and those who contribute ideas for defense is the only way freedom and peace can survive.

Part I

The Beginnings of the MED

Groves describes how he was unexpectedly assigned in September 1942 to lead the Army’s atomic bomb effort—a project he considered less important than overseas combat command—and how the Manhattan Engineer District was organized, named, and set in motion despite severe priority shortages, incomplete science, and no clear plan.

• Groves was deeply disappointed to receive the Manhattan assignment in September 1942, viewing it as less significant than combat duty and initially unimpressed by the project’s scientific foundation, which rested more on theory than proven knowledge.
  • General Somervell told Groves the Secretary of War and the President had selected him for the assignment and that if he did the job right it would win the war.
  • Groves noted that the project was estimated at less than $100 million—far less than the Corps of Engineers spent in a normal week—and what he knew of it had not particularly impressed him.
• The scientific background of the project stretched from Lise Meitner’s 1939 explanation of uranium fission through Einstein’s letter to Roosevelt and the establishment of the S-1 Committee, with European refugee scientists consistently more alarmed than American-born physicists about military applications.
  • Alexander Sachs carried Einstein’s letter to the White House, leading Roosevelt to appoint the Advisory Committee on Uranium.
  • Glenn Seaborg’s group at UC Berkeley created the first submicroscopic amounts of Plutonium-239 in March 1941 and confirmed it fissioned as readily as U-235.
• The name ‘Manhattan Engineer District’ was chosen for the project because Marshall’s main office was in New York City, replacing the security-compromising designation ‘Laboratory for the Development of Substitute Materials.’
  • Groves objected to the DSM name on security grounds, feeling it would arouse curiosity, and the name ‘Manhattan’ was chosen as the least likely to draw attention.
  • The Tennessee site near Clinton, later known as Oak Ridge, was selected for its TVA power supply, adequate water, year-round construction climate, and reasonable isolation.
• Groves secured an AAA priority rating from War Production Board chairman Donald Nelson in September 1942 by threatening to recommend the project be abandoned if the WPB would not cooperate—resolving what he saw as the project’s greatest single obstacle.
  • The project had been operating on an AA-3 priority, the highest then available, which was wholly inadequate; Stone and Webster estimated the same construction job would take three months less under AA-1.
  • Nelson’s immediate capitulation when Groves threatened to go to the President eliminated major priority difficulties for nearly a year.
• The Military Policy Committee—comprising Bush (with Conant as alternate), Admiral Purnell, and ultimately General Styer rather than Groves—was established at a September 23, 1942 meeting chaired by Secretary Stimson to provide policy oversight without the unwieldy nine-person group originally proposed.
  • Groves argued successfully for a committee of three rather than seven or nine, on the grounds that he could keep three people informed and obtain their advice readily.
  • Groves was later replaced by Styer on the committee, a change he came to see as advantageous because Styer’s seniority gave the project better access to Army Services of Supply.

First Steps

Groves describes establishing his lean Washington headquarters, addressing the project’s dire priority and organizational weaknesses, and making key early decisions about personnel—including his selection of General Farrell as his designated successor—that would shape the entire enterprise.

• Groves deliberately maintained a minimal headquarters of initially two rooms and fewer than a dozen staff, modeled on General Sherman’s lean command philosophy, believing large staffs bury leaders’ capacity for prompt decisions under indecisive studies.
  • The Washington office grew to only seven rooms by a year into the project, with dispersed sub-offices in New York that compartmentalized activities and reduced cross-chatter.
  • His secretary Mrs. O’Leary became his chief administrative assistant, and he twice had to reassign his intended executive officers to urgent field positions.
• Groves replaced Colonel Marshall with Nichols as District Engineer in August 1943, choosing Nichols based on his extraordinary grasp of technical and scientific details and their prior service together in Nicaragua, while simultaneously releasing as many regular officers as possible to combat assignments.
  • Groves believed strongly that in wartime every possible regular officer should be in the combat area, a view shaped by his own experience as a West Point cadet who missed World War I.
  • In retrospect, Groves concluded it was a mistake not to have kept more regular officers in the project, as the postwar years suffered from a lack of officers experienced in atomic work.
• Secretary Stimson refused to let Groves fly to London to meet Churchill in December 1944, telling him ‘you can’t be replaced,’ which forced Groves to identify and secure General Thomas F. Farrell as his designated successor through a process that gave Nichols veto power over the selection.
  • Groves drew up a list of six acceptable officers and told Nichols to strike any he found unacceptable, including—without hesitation—Nichols’s first deletion, who was a close personal friend of Groves.
  • Farrell was the first choice of both men; he had been Chief Engineer of New York State and Groves’s former executive officer, and proved of inestimable value during the climactic summer of 1945.
• Groves insisted on being promoted to brigadier general before officially taking charge, correctly calculating that rank would matter more to the academic scientists he would supervise than it did among soldiers.
  • His later experience convinced him this was wise: the prerogatives of rank, he found, were more important in the academic world than in the Army.

The Uranium Ore Supply

Groves recounts how Edgar Sengier of Union Miniere had stored over 1,250 tons of extraordinarily rich Belgian Congo uranium ore on Staten Island before the war, and how Colonel Nichols secured it on the basis of a handshake in September 1942—a discovery Groves calls the single most important chance event enabling Allied success.

• Edgar Sengier, managing director of Union Miniere, had shipped over 1,250 tons of uranium ore from the Shinkolobwe Mine in the Belgian Congo to a Staten Island warehouse in 1940, motivated by a warning from Sir Henry Tizard that the material could be catastrophic if it fell into enemy hands.
  • The Shinkolobwe ore was of exceptional richness—hand-sorted material averaged over 65% uranium oxide, compared to 0.2% for marketable Colorado Plateau ore and 0.03% for South African ore.
  • Sengier had tried three times in 1942 to alert the State Department to the strategic value of the uranium, but was consistently ignored because the State Department was not informed of the atomic project until February 1945.
• Nichols secured the entire Staten Island uranium stockpile on September 18, 1942—the day after Groves took charge—in an hour-long meeting with Sengier, sealed by handshake, with written contract details to follow later; this was the standard MED practice for major acquisitions.
  • Sengier, wary after being ignored by the State Department, opened by asking Nichols whether he had come to talk or to do business.
  • The agreement also covered all richer aboveground uranium ore in the Belgian Congo, giving the Allies control of the world’s most important uranium source for the critical war years.

The Plutonium Project

Groves describes the decision to assign du Pont to design, build, and operate the plutonium production plants despite the process being entirely unproven—a decision complicated by fierce resistance from Chicago laboratory scientists who believed they could do the engineering themselves—and culminating in du Pont’s extraordinary agreement to take no fee and no patent rights.

• When Groves visited the Metallurgical Laboratory in October 1942, the Chicago scientists told him their estimate of how much fissionable material a bomb would require was accurate ‘within a factor of ten’—meaning the actual amount could be anywhere from one-tenth to ten times their estimate—which Groves found horrifying but ultimately inescapable.
  • Groves compared his position to that of a caterer told he must be prepared to serve anywhere between ten and a thousand guests.
  • This uncertainty about bomb material quantities plagued planning continuously until shortly before the Alamogordo test on July 16, 1945.
• Groves chose du Pont to design, build, and operate the plutonium plants because it was the only firm with the engineering capacity, chemical expertise, and construction experience to handle all three phases—a decision opposed by many Chicago scientists who believed fifty junior engineers under their supervision would suffice.
  • The Chicago scientists who thought they could design and build the plant themselves were proposing to handle what eventually required a peak construction force of 45,000 workers and strained even du Pont’s vast resources.
  • Compton warned Groves of likely opposition, particularly from European-trained scientists who thought all design should be under their personal direction, but agreed du Pont was by far the best choice.
• The first controlled nuclear chain reaction occurred at Stagg Field on December 2, 1942, under Fermi’s direction; Groves was en route from the Pacific Coast and learned of it via Compton’s coded telephone message to Conant: ‘The Italian navigator has just landed in the new world. The natives are friendly.’
  • Groves had serious misgivings about conducting the experiment in the heart of a populous area rather than the isolated Argonne site, but did not interfere with Compton’s plans.
  • The test proved controlled chain reaction was achievable but gave no assurance that plutonium could be produced on a large scale or that a bomb using it would explode.
• Du Pont agreed to accept the contract for the plutonium plant on the condition that it receive no fee or profit of any kind and no patent rights—a decision made by the Board of Directors without a single member reading the faced-down secret papers before voting approval.
  • A legal fee of one dollar was included for purely legal reasons; after V-J Day government auditors disallowed part of it since the contract period had not fully elapsed, requiring du Pont to return thirty-three cents to the United States.
  • The government assumed full responsibility for all unusual hazards, including possible catastrophic damage to du Pont’s reputation in the event of a major accident, since normal insurance was impossible under security constraints.

Los Alamos: I

Groves explains how he selected Oppenheimer as director of Project Y over security objections and despite the absence of a Nobel Prize, then chose Los Alamos as the site for the weapons laboratory after rejecting a hemmed-in New Mexico valley and recognizing the advantages of an existing boys’ school on an isolated mesa.

• Groves chose Oppenheimer as director of Project Y despite strong opposition, unresolved security concerns about past associations, and his lack of a Nobel Prize, because no one else available combined theoretical mastery with administrative potential—and in July 1943 Groves personally signed the order clearing him ‘irrespective of the information’ on file.
  • Ernest Lawrence could have done the job but could not be spared from the electromagnetic separation process, which only he could carry through to success.
  • When Groves put the question before the Military Policy Committee and asked each member to name a better candidate, within weeks it became apparent none could be found.
• Los Alamos was selected over other southwestern sites primarily because it was isolated, had room for expansion, already had buildings from a boys’ school, and the school’s owners were eager to sell—avoiding the condemnation proceedings that would have attracted attention.
  • A site in a New Mexico valley was rejected because cliffs on three sides would have depressed workers and made expansion impossible.
  • Security was enhanced by geographic isolation: few roads and canyons provided access, and the enforced isolation of personnel reduced inadvertent diffusion of secrets to outside friends.

Hanford: I

Groves explains how safety concerns about operating plutonium reactors near Knoxville’s population and power grid drove the decision to locate the production plant in the remote Hanford area of Washington State, where a reconnaissance team—sent partly to test the compatibility of Colonel Matthias and du Pont’s Church—returned unanimously enthusiastic.

• The plutonium production plant was moved from Oak Ridge to a remote site after du Pont’s Carpenter suggested that a reactor explosion scattering radioactive material toward Knoxville could catastrophically disrupt war production, compromise security, and trigger a Congressional investigation that would end all others.
  • General Somervell half-jokingly told Groves he was buying a house near the Capitol because both of them would spend their lives before Congressional committees if the project failed.
  • The Hanford site required a rectangle approximately 12 by 16 miles for the hazardous manufacturing area, with no town of 1,000 people closer than 20 miles to any pile or separation plant.
• The Hanford site was chosen because the high-voltage power line from Grand Coulee to Bonneville ran through it with a substation at its edge, and the next-best site had been converted to an aerial gunnery range whose takeover would have drawn undue attention.
  • The reconnaissance party scoured the West for two weeks before returning unanimously enthusiastic about the Hanford area, near the Columbia River with its superabundance of very pure, cold water.
  • The soil was mostly sand and gravel—almost ideal for heavy construction—and most farms conveyed the impression that owners were having difficulty making them pay, limiting condemnation costs.
• Groves’s decision to let Hanford farmers harvest one more crop before taking possession—intending fairness—backfired when an unusually good growing season drove up jury verdicts on land values, because Yakima juries applied their own rich farmland values to Hanford’s marginal agricultural land.
  • The federal judge allowed juries to feel the government was not approaching the cases with clean hands, making it virtually impossible to stem excessive awards.

Hanford: II

Groves details the unprecedented engineering challenges of building the Hanford plutonium reactors and separation plants—including water purity, shielding, remote maintenance, radioactive waste storage, and the protection of Columbia River salmon—and the management of a massive, isolated workforce that required as much attention to women’s shoes and community morale as to reactor physics.

• Hanford’s reactors were switched from helium to water cooling in February 1943 after engineers determined that helium’s radioactivity would make equipment maintenance nearly impossible, and the Columbia River—fortunately free of dissolved chemicals requiring more than normal treatment—provided the necessary cooling.
  • A $6-10 million deionizing plant was authorized in a snap decision when Dr. Hilberry said he didn’t think it was needed but couldn’t do without it if it was—and Groves never needed it.
  • Cooling water leaving the pile was conducted underground to retention basins for radioactive decay before discharge into the Columbia, protecting both fish and downstream human populations.
• Every major Hanford design decision had to be made before the Clinton semi-works pile was even operational, and many before plutonium had been separated in more than submicroscopic quantities—requiring unprecedented engineering leaps based on almost no empirical data.
  • Seven months of effort by the Aluminum Company of America were required just to perfect aluminum tubing of the proper characteristics for the pile.
  • Welding of the surrounding steel plates had to be near-perfect, requiring a special super-classification of welders with premium pay and periodic practical examinations.
• Maintaining a stable female clerical workforce at the isolated Hanford site required proactive management of living conditions, community programs, and morale—exemplified by Mrs. Steinmetz’s rapid response to practical complaints like gravel that destroyed rationed shoes, which was paved over the next day after she mentioned it.
  • Many women arrived expecting Washington’s evergreen forests and found a sagebrush desert after a forty-five-mile overnight bus ride from the train station, without their luggage.
  • Red Cross and Girl Scout programs organized at a community meeting—held while workmen simultaneously reroofed the building and poured a new floor—are still in existence at Richland decades later.

Oak Ridge

Groves describes the three uranium separation plants at Oak Ridge—electromagnetic (Y-12), gaseous diffusion (K-25), and thermal diffusion (S-50)—explaining how each was built and operated under conditions of unprecedented scientific uncertainty, extraordinary industrial scale, and tight secrecy, culminating in the July 24, 1945 deadline when enough uranium was shipped to Los Alamos for the Hiroshima bomb.

• The Y-12 electromagnetic plant—built by Stone and Webster, operated by Tennessee Eastman, and using silver borrowed from the Treasury Department because wartime copper was unavailable—was the first to operate and the only plant producing the final enriched uranium product until December 31, 1946.
  • More than 14,000 tons of silver worth over $300 million were borrowed from the Treasury at West Point and fabricated into magnet coils; only 0.035% was lost over the entire operation.
  • When Colonel Nichols asked the Under Secretary of the Treasury for 5,000 to 10,000 tons of silver, he received the icy reply: ‘Colonel, in the Treasury we do not speak of tons of silver; our unit is the Troy ounce.’
• The K-25 gaseous diffusion plant—whose barrier material, the heart of the process, could not be produced satisfactorily until late 1944—required $200 million in construction spending before engineers even knew whether a workable barrier could be made in the necessary quantities.
  • The entire plant design was based on a barrier piece no larger than a silver dollar; even that small foundation was invalidated when it became known the material used in the first filter could never be employed in the main plant.
  • A special school trained over 200 employees in leak detection using helium gas and improved mass spectrometers, because total leakage through hundreds of miles of piping had to be less than through a single pinhole.
• The S-50 thermal diffusion plant—suggested by Oppenheimer in June 1944 as a first-stage enrichment feed for other processes—was built in just 69 days to preliminary operation by the H. K. Ferguson Company, demonstrating the project’s capacity for extreme speed when properly directed.
  • Oppenheimer was the first to realize that thermal diffusion could be used as a preliminary enrichment step feeding the electromagnetic plant, and Groves regretted not thinking of it a year earlier when it could have been built larger.
  • Peak production was reached in June 1945, directly contributing to having enough uranium for the Hiroshima bomb by the July 24 deadline.
• Labor relations at Oak Ridge were generally excellent—with only 8,000 man-hours lost to work stoppages against 67 million worked—partly because a young union organizer voluntarily stood down an organizing drive at the powerhouse after Groves explained that unionization would compromise security.
  • “The organizer told Groves: ‘In view of what you have told me about the importance of this work… I want to assure you that we’ll make no effort to organize these men; we’ll discourage any effort that is made, with the full realization that this means these men will not belong to our union.’” —Fred Behler
  • At Hanford, by contrast, Groves and du Pont’s Read were unable to persuade pipefitters’ union head M. P. Durkin in Chicago to increase production, ultimately resolving the shortage by furloughing Army pipefitters to civilian work.

Negotiations With The British

Groves traces how the British-American atomic information relationship evolved from open interchange to increasingly restricted exchange as the American program grew to dominate—culminating in the Quebec Agreement of August 1943, which Groves credits to Bush’s skillful negotiation that corrected a garbled presidential cable that would have given Britain unrestricted access.

• By late 1942 it was clear that information flow would be almost entirely one-way—from the US to Britain—and Groves, Bush, and Conant concluded that exchange should be limited to information that would assist the war effort, not postwar commercial or military purposes, a position consistently opposed by British representative W. A. Akers.
  • Bush and colleagues felt that Akers was influenced by undue regard for postwar commercial advantages for the British, citing British precedents of withholding information from the US on the same grounds.
  • The Military Policy Committee’s December 1942 report to Roosevelt recommended Alternative C—restricted interchange only to the extent recipients could use it now—and Roosevelt approved.
• The Quebec Agreement of August 17, 1943 established the Combined Policy Committee governing US-UK-Canada atomic collaboration; its relatively equitable terms resulted from a garbled cable that prevented Bush from learning in time of Roosevelt’s July 20 instruction for ‘complete exchange of all information.’
  • “Conant wrote before the July 22 London meeting: ‘A complete interchange with the British on the S-1 project is a mistake… whatever time devoted to British interchange will be a pure waste of time as far as the job of winning this war is concerned.’” —James B. Conant
  • Churchill modified his position at the July 22 meeting to accept interchange limited to war purposes, and the resulting Quebec Agreement closely matched the draft Sir John Anderson had already presented to Bush in Washington.

Security Arrangements And Press Censorship

Groves explains how the MED’s security was organized around rigid compartmentalization of knowledge, close cooperation with the FBI, and voluntary press censorship administered through the Office of Censorship—and how the most damaging security breach came from Klaus Fuchs, whose Communist background the British had been warned of but failed to record.

• Compartmentalization—each person knowing everything needed to do their job and nothing else—was the heart of MED security, and it served dual purposes: limiting espionage exposure while also improving operational efficiency by keeping people focused on their specific tasks.
  • Security was not the primary object of the Manhattan Project; the mission was to develop the bomb, and security was an essential element but not all-controlling.
  • The three security aims were: keeping Germany from learning of technical advances; ensuring complete surprise when the bomb was first used; and keeping the Russians from learning designs and processes.
• Klaus Fuchs’s admission to the project was a mistake enabled by British security failures: Germany had warned British authorities before the war that Fuchs was a Communist, but the British did not record it, interned him as an enemy alien, then released him, granted him citizenship, and provided a misleading clearance statement to Groves.
  • Fuchs knew the general progress of atomic development through fall 1942, the gaseous diffusion plant details, designs for both gun-type and implosion weapons, and MED thinking about the hydrogen bomb.
  • Groves concluded the basic reason for the British failure was the prevailing attitude that for an Englishman treason was impossible, and that foreign-born citizens automatically acquired native-born loyalty.
• Press censorship was achieved through voluntary cooperation with the Office of Censorship under Byron Price, with decoy words like ‘yttrium’ added to the banned list to disguise its true purpose, while the Knoxville papers were allowed local social items about Oak Ridge but nothing disclosing its purpose.
  • A radio program discussing atomic explosion possibilities nearly broke security when a station failed to review a script prepared by someone who had gleaned information from project scientists; Groves concluded there was no deliberate breach.
  • A Congressman’s comment in the Congressional Record about the importance of the Hanford Project was republished in a newspaper Groves suspected did so deliberately to demonstrate the limits of his press prohibitions.

Los Alamos: II

Groves describes the administrative and scientific organization of the Los Alamos laboratory—its early hardships, the selection of Parsons as ordnance chief, the development of both gun-assembly and implosion bomb designs, and the ongoing tension between scientists and military personnel that Oppenheimer’s leadership largely managed to contain.

• The University of California was selected as the Los Alamos contractor, with Oppenheimer building his team from Berkeley colleagues and Conant’s Harvard network; the original plan for 100 scientists grew to thousands, and an early promise to grant all civilians military rank was abandoned as impractical.
  • Scientists had complete freedom in choosing jobs and had to be persuaded to come despite the disadvantages of isolation, security restrictions, and their natural disinclination to move their comfortably situated families.
  • Oppenheimer received less salary than some of his subordinates because he came from a state university; Groves eventually raised it without any request from Oppenheimer himself.
• Commander William Parsons was selected as ordnance chief at Los Alamos after Bush proposed a naval officer and Purnell endorsed him; his background in proximity fuse development and regular military status proved invaluable for bridging the civilian scientists and the bomb delivery mission.
  • Parsons arrived at Los Alamos to find a sentry who telephoned his sergeant: ‘We’ve really caught a spy! A guy is down here trying to get in, and his uniform is as phony as a three dollar bill. He’s wearing the eagles of a colonel, and claims that he’s a captain.’
  • His selection was agreed to by Bush, Purnell, Oppenheimer, and Groves as meeting all requirements: practical and theoretical ordnance expertise, military credibility, and the ability to attract scientific respect.
• The discovery in late 1943 that plutonium’s previously unknown properties made it extremely difficult to use safely in a gun-type bomb made the implosion design—championed by S. H. Neddermeyer against initial skepticism—suddenly critical, validating his persistence and doubling Los Alamos’s staff.
  • The gun-assembly Thin Man bomb design was well understood from early on; the implosion Fat Man was far harder because there was no prior experience on which to base its design.
  • A Review Committee recommendation that the Los Alamos laboratory take responsibility for purifying plutonium after separation, and Kistiakowsky’s Explosives Division, were added as bomb complexity grew.
• The weekly colloquium that all sufficiently trained staff could attend was a major security hazard—one of the reasons Fuchs’s treachery was so damaging—but was maintained because it served the morale function of keeping scientists connected to common purpose.
  • The mail censorship established in December 1943 was intended primarily to guard against inadvertent rather than intentional disclosure; deliberate espionage could never be prevented by normal censorship and had to rely on individual integrity.
  • Travel restrictions lifted in fall 1944 caused general rejoicing; Groves judged the improvement in morale would outweigh the increased security risks.

The Combined Development Trust

Groves describes the creation of the Combined Development Trust—a tripartite US-UK-Canada agency to secure long-term rights to Belgian Congo uranium—and the wider geological survey effort that discovered uranium in South African gold mine tailings and other global sources, transforming postwar uranium availability.

• The Combined Development Trust was established through the Declaration of Trust signed by Roosevelt and Churchill in June 1944, following negotiations in London that Groves managed through Ambassador Winant, to secure exclusive long-term rights to Belgian Congo uranium before British postwar interests could gain a monopoly.
  • The Trust’s last clause—inserted at Groves’s insistence—required that signatories recommend the agreement’s extension by treaty after the war, reflecting his belief that international agreements should receive Senate approval as provided in the Constitution.
  • To fund uranium purchases under a long-term commercial contract that could not be covered by appropriated war funds, $37.5 million was deposited in Groves’s personal account at the US Treasury, drawn against as needed.
• A geological survey by Union Carbide, supervised by geologist George Bain, discovered uranium in South African Rand gold mine tailings—a finding experts had considered impossible—eventually enabling a South African uranium export industry worth over $150 million annually by 1959.
  • Bain took a sample of Rand gold-bearing rock home to Amherst on a Sunday, placed it on a photographic plate, and found beta ray intensity indicating far more uranium than previously suspected.
  • A method for extracting uranium from Rand waste was developed by MIT’s Dr. Gaudin and later improved by South Africans, enabling gold mines that would otherwise have been uneconomical to continue operating.

Military Intelligence: Alsos I—Italy

Groves describes the formation of the Alsos mission to exploit Italian sources for intelligence on German atomic progress, and how its largely negative findings—no evidence of intense German nuclear activity—were initially discounted, but ultimately provided a sound baseline for concluding Germany had not yet passed the stage the US reached in mid-1942.

• The Alsos mission to Italy was created because Groves and General Strong recognized that as Allied forces advanced up the Italian peninsula they would encounter scientists and documents that could reveal German atomic progress—intelligence none of the existing agencies was well positioned to collect.
  • Code name ‘Alsos’—Greek for ‘grove’—was given by G-2 in what Groves considered a careless security breach; he decided changing it would draw more attention than keeping it.
  • The mission was commanded by Lieutenant Colonel Boris T. Pash, who had made an impression on Groves through security work at Berkeley, and included scientists from both the War Department and the Navy.
• The Italy mission’s primary finding was essentially negative—almost no evidence of German nuclear explosive development—but this conclusion was discounted precisely because it was negative, and Groves took it as evidence that Germany had not yet reached the stage the US reached when the Army entered in mid-1942.
  • Interviews with Italian physicists at Naples, Taranto, and Brindisi confirmed that the most valuable sources were in still-occupied Rome, which the mission could not reach.
  • The mission’s recommendation to establish similar intelligence operations following the anticipated invasion of Western Europe was concurred in by both Groves and the new G-2, General Bissell.

A Serious Military Problem

Groves describes his most consequential pre-D-Day decision: recommending that General Eisenhower be warned of the possibility—which Groves himself considered unlikely—that the Germans might use radioactive material to block the D-Day landings, while simultaneously advising that invasion plans proceed as if this would not happen.

• In March 1944, Groves recommended warning Eisenhower of the possibility that the Germans might lay radioactive barriers along invasion routes, primarily because the Germans could produce fission byproducts easily and had demonstrated willingness to disregard civilian welfare—but he advised that invasion plans proceed unchanged.
  • Groves’s March 22 memorandum to Marshall stated: ‘Radioactive materials are extremely effective contaminating agents; are known to the Germans; can be produced by them and could be employed as a military weapon.’
  • To prepare the medical corps without revealing the true danger, Chief Surgeon General Hawley issued orders under cover stories about fogged photographic film and an epidemic disease of unknown etiology—actually radiation exposure symptoms.
• Eisenhower’s response—informing only a handful of senior commanders, earmarking special equipment, and establishing medical channels under suitable cover—demonstrated he fully understood that Groves considered the threat unlikely but that ignoring it entirely would have been irresponsible.
  • Eisenhower’s May 11 letter to Marshall noted that since the Combined Chiefs had not officially raised the matter, he assumed they considered it unlikely, and he had consequently not briefed the operational commanders.
  • When the Allied troops landed without radioactive interference, Groves felt more than a bit relieved, recognizing he had assumed enormous personal responsibility with his recommendation.

Military Intelligence: Alsos II—France

The reconstituted Alsos mission under Pash and Goudsmit entered liberated Paris ahead of French armor on August 25, 1944, interrogated Joliot-Curie, and began the systematic hunt through France and the Low Countries for German uranium, scientists, and laboratory records—recovering 68 tons of ore from Belgium and determining that Germany’s atomic program remained in experimental stages.

• Samuel Goudsmit was appointed scientific chief of the reconstituted Alsos mission because as a capable atomic physicist not involved in the MED himself, he could interrogate German scientists without revealing the scope of American progress—and Calvert’s pre-D-Day intelligence work gave the mission a comprehensive target list before it landed.
  • “Goudsmit observed of German scientists: ‘On the whole, we gained the definite impression that German scientists did not support their country in the war effort. The principal thing was to obtain money from the government for their own researches, pretending that they might be of value to the war effort.’” —Samuel A. Goudsmit
  • Pash’s team entered Paris on August 25, 1944, directly behind the first French armored tank in the liberation column, in an open jeep, before reaching Joliot’s laboratory that evening.
• Documents captured at Strasbourg in November 1944 provided the most significant Alsos intelligence to date, establishing definitively that Germany’s atomic program as of late 1944 remained in experimental stages and had been apprised of nuclear weapon possibilities in 1942 but chose not to pursue them seriously.
  • Through notes of meetings, fragments of computations, and hints in personal correspondence, Alsos assembled a revealing picture of the German nuclear research program from ostensibly unclassified documents.
  • Alsos also recovered 68 tons of Belgian Congo uranium ore stored in Belgium—ore the Germans had confiscated in 1940—and dispatched it to the United States through England.

The Problem of The French Scientists

Groves explains how a 1942 British agreement with French scientist von Halban—made without informing the Americans—gave Joliot-Curie enough information about Allied atomic progress to use as diplomatic leverage, enabling France to threaten turning to Russia and acquire bargaining power entirely disproportionate to her actual atomic contributions.

• The British had secretly agreed in September 1942 to share atomic information with French scientists von Halban and Kowarski in exchange for patent rights, without informing the Americans—a commitment that violated the spirit of the Quebec Agreement signed the following year, which specifically prohibited sharing information with third parties.
  • Sir John Anderson acknowledged the obligation without disclosing its full terms until pressed; the Americans were astonished to learn of it only when Anderson sought permission to share information with the French.
  • Von Halban was sent to Paris in November 1944 ostensibly to persuade Joliot not to press France’s demands, but instead disclosed vital classified information about American atomic research that Joliot could not otherwise have known.
• Joliot leveraged his acquired knowledge of Allied progress to tell Anderson in February 1945 that if France were not admitted to full atomic collaboration, she would have to turn to Russia—giving France diplomatic power out of all proportion to her early patents, and forcing the US to sit quietly while military security was compromised by allies it could not control.
  • Groves’s sole satisfaction came from a remark Joliot made to a US Embassy employee: while the British had always been cordial and given him much information, he got virtually nothing from the Americans he encountered.

Military Intelligence: Alsos III—Germany

Pash and the Alsos mission raced through Germany ahead of and in violation of Allied zone boundaries to capture Heisenberg, Hahn, and the other German nuclear scientists, seize their pile components at Haigerloch, and recover over 1,100 tons of uranium ore at Stassfurt before the Russians could reach any of it—confirming that Germany had never progressed beyond laboratory-stage experimentation.

• Groves recommended and General Marshall approved the destruction of the Auer-Gesellschaft works at Oranienburg by the Eighth Air Force in March 1945, rather than allowing Alsos to seize it, because it lay in what would become the Soviet zone and destroying it was the only way to deny its uranium processing capability to the Russians.
  • 612 Flying Fortresses dropped 1,506 tons of high explosives and 178 tons of incendiary bombs in 30 minutes on March 15, 1945; as a bonus, a simultaneous attack on Zossen incapacitated General Guderian, Chief of the German General Staff.
• Operation Harborage—sending American troops diagonally across the French zone of advance to seize the Hechingen-Haigerloch-Tailfingen area where the German atomic scientists and their pile were concentrated—required Groves and Stimson and Marshall to kneel almost on the floor to find the target on a wall map.
  • The State Department refused to adjust occupation zone boundaries to include the area without a full explanation Groves would not give; Stimson decided further argument was not feasible and instead planned the cross-zone military operation.
  • Pash captured the Haigerloch pile on April 23, Hechingen and its physicists on April 24, and Hahn and von Laue in Tailfingen on April 25—all before French forces arrived.
• Lansdale’s team recovered approximately 1,100 tons of Belgian Congo uranium from the WIFO salt mine near Stassfurt—the bulk of the supply Germany had confiscated in 1940—using a requisitioned barrel factory, exhausted Negro truck drivers, and three days and nights of continuous loading before the Russians arrived.
  • “General Bradley dismissed Sibert’s hesitation about possibly disturbing the Russians with the terse words: ‘To hell with the Russians.’” —Omar Bradley
  • British officer Sir Charles Hambro was in his World War I Coldstream Guards uniform; the ore’s rusty brown color led British troops to guess it was gold and Americans to guess it was whiskey, from the ‘Calvert’ route signs.
• Germany’s atomic program never advanced beyond laboratory experimentation because it lacked unified direction, suffered from competing groups that did not share information, and most German scientists had come to believe a nuclear weapon was impractical—a conclusion Heisenberg reinforced by mistakenly thinking they would need two tons of U-235 because they did not understand fast neutron bomb design.
  • “Heisenberg admitted at Farm Hall that his group would not have had ’the moral courage to recommend to the government in spring 1942 that they should employ 120,000 just for building the thing up.’” —Werner Heisenberg
  • German scientists discussed at Farm Hall whether their failure was due to lack of desire rather than capability; Bagge explicitly rejected Weizsäcker’s claim that physicists had not wanted Germany to win.

Part II

Training The Air Unit

Groves describes organizing the 509th Composite Group under Colonel Tibbets at Wendover Field, Utah, securing sufficient B-29s from General Arnold through direct personal appeals that bypassed Air Force staff resistance, and preparing the group for a single-plane delivery tactic that General LeMay proposed at their first meeting.

• General Arnold committed unreservedly to the Manhattan Project’s air requirements on two critical occasions—first providing enough modified B-29s over staff objections, then ordering fourteen new replacement aircraft rather than let the Air Force be responsible for any failure—because he understood the project’s magnitude.
  • Wilson told Groves the only way to get the planes was to see Arnold personally; Arnold’s immediate agreement so impressed Wilson that he noted Groves’s visit had made all MED requests non-negotiable with Air Force staff.
  • “Arnold told Groves: ‘In view of the vast national effort that has gone into the Manhattan Project, no slip-up on the part of the Air Force is going to be responsible for a failure.’” —H. H. Arnold
• Colonel Paul Tibbets was selected to command the 509th because he was probably the most experienced B-29 pilot in the service, having flown the North African and European campaigns before returning to test the B-29 and write its combat instructions—though Groves later regretted that the group’s officers were not more systematically selected from men likely to remain in regular service.
  • Sixteen years after Hiroshima and Nagasaki, only four men remained on active duty: Tibbets, weaponeer Ashworth, and bombardiers Ferebee and Beahan.
  • The 509th’s long-range over-water training in Cuba—flying singly rather than in formation—proved fortuitous when LeMay adopted single-plane missions, because it had built navigational self-sufficiency that standard formation bomber training did not.

Choosing The Target

Groves explains how he established target criteria centered on military and psychological impact, how the Target Committee selected four cities, and how Secretary Stimson’s personal veto of Kyoto—the target Groves most preferred for its size—proved wise in retrospect by reducing casualties and avoiding permanent damage to US postwar standing.

• The target criteria required cities whose bombing would most adversely affect Japanese will to continue the war, that were military in nature, that had not been previously damaged by air raids, and—crucially—that were large enough to allow complete assessment of bomb effects within city limits.
  • Groves had always insisted casualties from direct radiation and fallout be held to a minimum, planning a high air burst that would largely confine injuries to non-radioactive blast and fire effects.
  • The four initially selected targets were Kokura Arsenal, Hiroshima, Niigata, and Kyoto, with all four reserved from conventional bombing by order to the Army Air Force in Guam.
• Secretary Stimson vetoed Kyoto—Groves’s preferred target because of its size—based on its cultural and religious significance to Japan and his concern for the historical position the United States would occupy after the war, and maintained this veto even after Groves repeatedly urged its inclusion from Potsdam.
  • Stimson had visited Kyoto when he was Governor General of the Philippines and was deeply impressed by its ancient culture; he was adamant that its bombing would damage America’s postwar position even if Groves argued it was militarily significant.
  • Groves came to be grateful he was overruled: if Kyoto had not been recommended as an atomic target, it would not have been reserved from conventional bombing and might have been seriously damaged before the war ended.
• General Marshall’s instruction to Groves—‘Is there any reason you can’t take this over and do it yourself?’—was a complete surprise and constituted the only directive Groves ever received for planning the bombing operations, giving him responsibility for selecting targets, drafting directives, and overseeing combat execution.
  • Groves had expected to be told to work through the Operations Planning Division of the General Staff; Marshall’s preference to keep knowledge restricted prevented that normal channel.
  • Admiral Leahy, who told Groves no weapon developed during a war had ever been decisive in that war, never had confidence in the atomic bomb’s practicability—making formal Joint Chiefs authorization of operations politically difficult.

Tinian

Groves explains the selection of Tinian over Guam as the operational base, the critical role of Colonel Kirkpatrick as his personal representative ensuring facilities were ready despite the island’s chaotic unloading priorities, and the assembly of the specialized Los Alamos team that would prepare the bombs for combat delivery.

• Tinian was chosen over Guam because it was 100 miles closer to Tokyo—potentially decisive given the B-29’s maximum-load fuel margin—and because facilities could be ready sooner, despite the administrative advantages of Guam’s harbor and maintenance infrastructure.
  • Tibbets’s Caribbean training experience suggested the 509th could expect to lose approximately five out of every forty engines on a round trip comparable to the Japan mission.
  • Colonel Kirkpatrick’s presence on Tinian was essential: his intervention through Captain Hill produced a direct Nimitz order to unload MED equipment immediately upon arrival, bypassing the normal three-month shipping backlog.
• LeMay’s proposal at their first meeting to use a single unescorted plane rather than a formation for each atomic mission was immediately accepted by Groves as sound because Japanese air defenses would likely assume a single high-altitude aircraft was on reconnaissance, and the 509th’s training had already prepared them for independent navigation.
  • This tactic contradicted standard Air Force practice in which formation lead navigators carried all navigational responsibility; the 509th’s Cuba training in single-plane operations proved critical.
  • The ‘Pumpkin’ bomb—containing 5,500 pounds of conventional explosives in Fat Man’s external shape—was used both for training and as a cover story explaining the 509th’s unusual mission to other Tinian units.

Alamogordo

Groves describes the Trinity test of July 16, 1945—including the weather crisis, his strategy of projecting calm to shield Oppenheimer’s decision-making, the explosion’s overwhelming light that surprised even those who designed it, and Fermi’s immediate impromptu blast measurement using torn paper scraps.

• The Trinity test was delayed three and a half hours by unfavorable weather, with Groves deliberately cultivating an atmosphere of calm and shielding Oppenheimer from contradictory advice, because the test date affected the Potsdam ultimatum’s timing and every additional hour of delay increased the risk of sabotage and equipment moisture damage.
  • When the weather forecasters failed to predict the rain and were visibly upset, Groves excused them and told Teller’s account: ‘After that, it was necessary for me to make my own weather predictions—a field in which I had nothing more than very general knowledge.’
  • Groves knew a successful test would affect the wording of the Potsdam ultimatum, and that every day’s delay in the test might mean a day’s delay in ending the war.
• The explosion at 5:30 a.m. on July 16, 1945, with an equivalent force of nearly 20,000 tons of TNT, so exceeded expectations that no one at the base camp was in a frame of mind to discuss next steps—the light alone was so far beyond any human previous experience that the shock wave’s comparatively gentle arrival came as an anticlimax.
  • Fermi measured the blast’s force by dropping torn paper scraps from a fixed height and measuring how far the shock wave carried them, accurately estimating the explosion’s power before instruments were read.
  • “When Farrell said ‘The war is over,’ Groves replied: ‘Yes, after we drop two bombs on Japan.’” —Leslie R. Groves
• Groves’s detailed Alamogordo report, drafted overnight and flown to Potsdam, reached Stimson on July 21 and was read to Truman and Byrnes that afternoon; Churchill told Stimson afterward that it explained why Truman had suddenly become forceful with the Soviets at the negotiating table.
  • “Churchill said: ‘Now I know what happened to Truman yesterday. I couldn’t understand it. When he got to the meeting after having read this report, he was a changed man. He told the Russians just where they got on and off and generally bossed the whole meeting.’” —Winston Churchill
  • The successful test and confirmation of readiness for the first Japan bombing by July 31 ‘froze’ the previously tentative decision to issue the Potsdam ultimatum.

Operational Plans

Groves recounts the logistics of moving the Hiroshima bomb components to Tinian—the uranium component aboard the USS Indianapolis, which was later sunk—and explains the July 23 written directive he drafted for Spaatz’s signature, which specified targets, authorized successive drops as materials became available, and retained control in Washington.

• The main uranium component for the Hiroshima bomb was transported by the cruiser USS Indianapolis to Tinian, arriving July 26; the Indianapolis was then sunk by a Japanese submarine on July 30 with approximately 900 crew, a tragedy Groves learned of only afterward and that he recognized as a very poor choice of carrier given her lack of underwater detection equipment.
  • The accompanying officers—Major Furman and Captain Nolan—were disguised as field artillerymen and were severely embarrassed by searching questions from the ship’s gunnery officers that they were wholly unprepared to answer.
  • Final small components of U-235 were flown to Tinian in two C-54s, with the second plane intended solely to mark the crash point if the first went down—prompting a senior staff officer to tell General George the operation was ‘unreasonable’ and ‘idiotic.’
• The July 23 directive Groves drafted for General Handy’s signature directed the 509th to deliver its first bomb after approximately August 3 on one of four targets as weather permitted, with additional bombs to follow as soon as ready—establishing that control resided in Washington and no communiques would be issued without prior War Department authority.
  • Groves’s understanding was always that the target date was August 1, but the words ‘after about 3 August’ in the official order reflected the date when readiness was expected at the time of signing, not a deliberate delay.
  • Spaatz’s cable about POW camps near targets was answered with authority to adjust aiming points to decrease chances of hitting any camp, but no change in targets—a decision Groves showed Stimson before sending, deliberately placing accountability with himself rather than the Secretary.

Hiroshima

Groves narrates the Hiroshima bombing of August 6, 1945—including Parsons’s decision to complete bomb assembly in-flight to reduce Tinian crash risk, the half-minute on-schedule arrival over target, and Groves’s tense overnight vigil in Washington waiting for confirmation that arrived six hours late due to a communications routing error.

• The Enola Gay dropped the Little Boy on Hiroshima at 9:15 a.m. on August 6, 1945—half a minute off a schedule set more than six hours earlier—with Parsons having completed final bomb assembly in-flight to reduce the risk of a crash contaminating Tinian, a decision Groves had opposed but could not reverse in time.
  • The bomb was dropped from 31,600 feet; fifty seconds later two shock waves hit the plane fifteen miles away, followed by a dark gray cloud over three miles in diameter and a column of white smoke rising to 35,000 feet.
  • Japanese authorities later estimated casualties at 71,000 dead and missing and 68,000 injured; photographic reconnaissance showed 60% of the city destroyed.
• Groves spent August 6 in Washington unable to receive the strike confirmation for hours due to a routing error that sent Farrell’s cable from Tinian through Manila rather than Guam, during which time he played tennis with an officer beside the telephone court, then worked at the Pentagon and finally received the strike message after 11 p.m.
  • “Parsons’s strike report read: ‘Results clearcut, successful in all respects. Visible effects greater than New Mexico tests. Conditions normal in airplane following delivery.’” —William S. Parsons
  • When Groves reported success to General Marshall the next morning, Marshall expressed feeling they should guard against too much gratification because of the large number of Japanese casualties; Groves replied he was thinking more about the men who had made the Bataan death march.
• William Laurence of the New York Times was embedded with the project from spring 1945, writing press releases under Groves’s direction and witnessing both Trinity and the Nagasaki mission as a pool correspondent—his Nagasaki dispatch later winning the Pulitzer Prize for best news story of the year.
  • A 1940 Saturday Evening Post article by Laurence on atomic energy had been so sensitive that in early 1943, Groves asked the Post to report any back-number requests and delay mailing until further instructions—though no such request was ever received.
  • The White House press release had been prepared and approved by Stimson and Truman weeks in advance; Groves made only a minor last-minute wording change rather than delay it pending visual damage confirmation from Hiroshima.

The Germans Hear The News

Groves reproduces transcripts from the secretly bugged Farm Hall detention facility showing that the German scientists were initially incredulous about the American bomb and quickly rationalized that they had chosen not to build one—while Heisenberg’s mistaken calculation that two tons of U-235 would be needed confirmed that Germany had never understood fast-neutron bomb design.

• The German scientists at Farm Hall responded to the Hiroshima announcement with initial disbelief, quickly moving to the rationalization that their failure had been a moral choice—a claim directly contradicted by Bagge and undermined by Heisenberg’s admission that German scientists lacked the moral courage to request the 120,000 workers the project would have required.
  • “Weizsäcker claimed: ‘I believe the reason we didn’t do it was because all the physicists didn’t want to do it, on principles. If we had all wanted Germany to win the war we could have succeeded.’” —Carl Friedrich von Weizsäcker
  • “Bagge immediately replied: ‘I think it is absurd for Weizsäcker to say he did not want the thing to succeed. That may be so in his case, but not for all of us.’” —Erich Bagge
• Heisenberg’s wonder about how the Americans separated two tons of U-235 for the bomb confirmed Goudsmit’s assessment that German scientists never understood fast-neutron bomb design and had been thinking in terms of dropping a full reactor—requiring far more material than the actual weapon needed.
  • “The Farm Hall scientists were also bugged discussing whether the British had installed microphones; Heisenberg laughed and said ‘They’re not as cute as all that. I don’t think they know the real Gestapo methods.’” —Werner Heisenberg
  • “Weizsäcker offered a prescient postwar observation: ‘Stalin certainly has not got it… the result will be a peace which will last until the Russians have it, and then there is bound to be war.’” —Carl Friedrich von Weizsäcker

Nagasaki

Groves describes the Nagasaki mission of August 9, 1945—marked by a fuel pump failure, a missed rendezvous with observation planes, three failed bombing runs over Kokura, and a last-second visual sighting over cloud-covered Nagasaki—resulting in a bomb that fell a mile and a half from the aiming point but destroyed two major Mitsubishi armament plants.

• The Nagasaki mission was plagued by problems—a defective fuel pump that stranded 800 gallons of unusable gas, a thirty-minute delay waiting for the missing observation plane, three failed runs over cloud-covered Kokura, and near-ditching fuel levels—but Beahan found a visual sighting hole over Nagasaki at the last moment and dropped the bomb off the planned aiming point.
  • “Admiral Purnell told pilot Sweeney before takeoff: ‘Young man, do you know how much that bomb cost?’ After Sweeney replied ‘$25 million,’ Purnell said: ‘See that we get our money’s worth.’” —W. R. E. Purnell
  • The bomb fell between two large Mitsubishi armament plants and destroyed both; Nagasaki’s hilly terrain limited destruction to 2.3 by 1.9 miles, compared to Hiroshima’s 1.7 square miles—causing an estimated 35,000 killed and 60,000 injured.
• After Nagasaki, Groves convinced General Marshall to hold all fissionable material shipments when it became clear Japan was about to surrender—a decision made without Stimson or Marshall being available due to armistice negotiations—because Groves judged it would be a terrible mistake to send another bomb when the war was effectively over.
  • Groves told Handy he would continue to hold all fissionable materials in the United States and would appreciate being able to inform Marshall at the earliest opportunity; Marshall later told Groves he was glad he had taken that action.
  • The Smyth Report—prepared by Henry Smyth of Princeton beginning in April 1944 and released on August 12, 1945—was Groves’s planned mechanism for controlling postwar information flow while meeting the inevitable public demand for details.

Part III

The MED And Congress

Groves describes how he secured funding for a $2.3 billion project through concealed appropriations and selective briefings of Congressional leaders, and how the project’s success was confirmed by Congressman Taber’s post-visit question: ‘Are you sure you are spending enough money at Oak Ridge?’

• The Manhattan Project’s entire $2.3 billion budget was obtained through concealed War Department appropriations, with only a handful of Congressional leaders—briefed by Stimson, Marshall, and Bush in February and March 1944—authorized to know the project’s purpose and ensure funds passed without scrutiny.
  • Speaker Rayburn, Majority Leader McCormack, and Minority Leader Martin agreed that no further explanation to the Appropriations Committee would be necessary, and arranged to have the items treated as matters of national security.
  • “The Comptroller General testified before the Senate Special Committee in April 1946: ‘We have audited every single penny expended on this project… it has been a remarkably clean expenditure.’” —Lindsay C. Warren
• After a 1945 inspection of Oak Ridge by Congressmen Cannon, Snyder, Mahon, Taber, and Engel, the reputation for frugality was so strong that Congressman Taber—famous for cutting government spending—asked Groves whether he was certain he was spending enough money.
  • “Under Secretary of War Patterson’s aide Jack Madigan summed up his multi-week inspection report in thirty seconds: ‘If the project succeeds, there won’t be any investigation. If it doesn’t, they won’t investigate anything else.’” —Jack Madigan
  • Senator Truman had agreed at Stimson’s request to delay any committee investigation of the project as a whole until either security permitted it or the war was over.

The Destruction of The Japanese Cyclotrons

Groves explains how the November 1945 destruction of five Japanese cyclotrons resulted from a chain of staff failures and miscommunications, with no single person at the policy level aware of what was happening until after the destruction was complete—and how Secretary Patterson’s frank public admission of error quickly defused the scientific community’s outrage.

• The cyclotrons were destroyed because a message drafted in Groves’s office—cleared as routine and dispatched without his personal review—ordered destruction, while a subsequent MacArthur cable announcing the destruction had begun was initialed and filed by subordinates without reaching any of the nine senior recipients, including Groves himself.
  • The officer handling the matter was new to the project and unaccustomed to the MED’s ways; an experienced officer would have questioned why Groves apparently wanted cyclotrons destroyed and, if Groves persisted, would have urged reconsideration.
  • MacArthur had actually opposed the destruction and tried to alert Eisenhower on November 28 to the conflicting instructions, but his cable also failed to reach Eisenhower personally.
• Secretary Patterson publicly admitted the destruction was a mistake made without proper consideration or scientific advice—signing the admission himself rather than attributing it to Groves by name—and the press’s surprise at such frank admission of error caused the story to quickly lose news value.
  • “Patterson’s statement read: ‘General MacArthur was directed to destroy the Japanese cyclotrons in a radio message sent to him in my name. That message was dispatched without my having seen it… The dispatch of such a message without first investigating the matter fully was a mistake. I regret this hasty action.’” —Robert P. Patterson
  • Groves drew the lesson that a commander must make his intentions unmistakably clear to subordinates, that even successful organizations fail when large numbers of untrained new people are introduced, and that honest errors openly admitted are sooner forgiven.

Transition Period

Groves describes the difficult demobilization period—replacing wartime reserve officers with hand-picked regular officers over General Staff objections, keeping Los Alamos viable under Norris Bradbury after Oppenheimer’s departure, deciding to keep the laboratory at its New Mexico site rather than relocate it to California, and initiating the radioactive isotope distribution program.

• Groves secured Secretary Patterson’s direct intervention to obtain the quality of regular officers he needed for the postwar MED, over the objections of Handy and Eisenhower who argued he was getting more than his share of the Army’s best—Patterson simply saying ‘I agree with Groves’ and directing complete freedom of choice.
  • Groves wanted West Point graduates ranked in the top 10% of their class, with successful athletic careers as a proxy for determination, because the scientists were extremely critical of anyone whose mental alertness did not equal or exceed theirs.
  • In retrospect, Groves concluded the policy of super-selection did not endure long enough and its demise is why the Army is no longer supreme in the nuclear warfare field.
• Groves selected Norris Bradbury as Oppenheimer’s successor at Los Alamos because, unlike the top four or five most famous scientists, he would see the directorship as a great opportunity, and because his Navy reserve officer status would help maintain relations between civilian scientists and military administrative officers.
  • Bradbury agreed to take the position on the understanding that after not more than five years he would return to academic life; fifteen years later, he was still there, his performance having exceeded the already very high expectations.
  • Groves decided to keep Los Alamos at its New Mexico site rather than relocate to southern California, reasoning that separating comfortable urban laboratories from experimental sites would create operational difficulty, lost time, and expense.
• The radioactive isotope distribution program—initiated without clear legal authority since appropriated military funds could not technically cover peacetime uses—began with a first shipment to St. Louis for bone cancer research and grew to an industry worth $500 million to $1 billion annually within about fifteen years.
  • Groves set prices to recover actual operating costs without profit or capital depreciation, believing material would be used more carefully if it were paid for.
  • Groves also started a commercial atomic power development study under Dr. Farrington Daniels at Wisconsin, intending to hand it off to the successor civilian agency—which then did not proceed on Daniels’s basis, causing a serious delay.

The AEC

Groves traces the legislative history of the Atomic Energy Act, arguing that despite a sustained propaganda campaign claiming the War Department sought to retain military control, both he and Patterson consistently testified in favor of civilian governance—and that the Act’s fatal flaw was establishing an executive commission rather than a board of directors with a single chief executive.

• Groves and Secretary Patterson consistently testified before both House and Senate committees that atomic energy responsibility should leave the War Department, that no single man should hold the power Groves had wielded, and that partisan politics must be kept out of atomic energy—directly contradicting the persistent propaganda that the War Department wanted to retain control.
  • Groves called the contrary propaganda ‘one of the most perfect brain-washing operations in modern times,’ effective primarily among better-educated Americans, maintained by people who knew it was false but used it for political advantage.
  • Senator Byrd suggested it might be better to leave atomic energy in Groves’s hands permanently; no committee member objected, giving Groves a de facto mandate by default during the long legislative delay.
• The Atomic Energy Act’s fundamental defect, in Groves’s view, was its executive commission structure—giving five commissioners equal powers—rather than a board of directors model with a single chief executive, because no executive group since Rome’s tribunes has ever functioned well.
  • Of the first five AEC general managers, three—Nichols, Fields, and Luedecke—were military officers who had to retire from active service to take the post, removing extremely capable officers from the active list.
  • The commissioners asked to delay their January 1 legal takeover date, putting Groves in the position of a caretaker who could make no major decisions during a period when major decisions were vital—and then largely declined to use the detailed cooperation he offered.

Postwar Developments

Groves reviews the postwar collapse of British-American atomic collaboration, Stimson’s visionary but unheeded September 1945 proposal for direct US-Soviet atomic negotiations, and the failure of international control efforts—concluding that the Baruch negotiations were doomed from the start when the Acheson-Lilienthal report was published before talks even began.

• The Hyde Park aide-mémoire—Roosevelt and Churchill’s secret September 1944 agreement for postwar full atomic collaboration—was found years later misfiled at Hyde Park in a naval folder because a clerk mistook ‘Tube Alloys’ for ship boiler tubes; its absence from American files created years of mutual incomprehension with the British.
  • The aide-mémoire specified: ‘Full collaboration between the United States and the British Government in developing Tube Alloys for military and commercial purposes should continue after the defeat of Japan unless and until terminated by joint agreement.’
  • Groves and Sir John Anderson drafted the postwar collaboration framework at Patterson’s direction, though Groves had not been invited to any of the Truman-Attlee-King meetings and had to deduce what the decisions had been.
• Secretary Stimson’s September 11, 1945 proposal to President Truman—to approach the Soviets directly and alone with an offer of controlled atomic information sharing before they developed their own bomb—was neither adopted nor seriously engaged, missing what Stimson saw as the only moment when negotiation from strength was possible.
  • Stimson warned against negotiating ‘with an atomic bomb ostentatiously at our hip,’ which could embitter the Soviets, and said the bomb was not merely another devastating weapon but a new force too dangerous to fit old concepts.
  • Bernard Baruch, head of the US delegation to UN atomic negotiations, later said the Russians would not countenance any effective system of international control, inspection, or punishment, and adamantly refused to give up the veto on such matters.
• The premature publication of the Acheson-Lilienthal Report—which Groves, Conant, and Bush had opposed publishing before negotiations began—gave the Soviets America’s final position as their starting point, effectively making the subsequent Baruch negotiations unwinnable.
  • The State Department blamed a Senate committee for the leak and the Senate blamed the State Department; journalists privately indicated the Senate was not responsible.
  • On balance, Groves concluded that the British contribution to the Manhattan Project was ‘helpful but not vital’ in technical terms, but that without Churchill’s political backing the project might never have been launched on the scale needed to succeed before the war ended.

A Final Word

Groves concludes that the Manhattan Project succeeded because of five factors—clear objective, compartmentalized specific tasks, positive unquestioned direction, maximum use of existing agencies, and full government backing with unlimited American capacity—and that atomic energy developed inevitably would have been first produced by a power-hungry nation without US action, making American development both necessary and fortunate for humanity.

• Atomic energy would have been developed somewhere in the mid-twentieth century regardless of American action; had a power-hungry nation been first, it would have immediately dominated the world, making American development not merely justified but essential for global freedom.
  • Groves argues that US atomic superiority in the postwar years averted catastrophic war without a complete surrender of principles, and enabled the first steps toward peaceful atomic uses.
  • The bombings of Hiroshima and Nagasaki ended World War II—they brought death and destruction on a horrifying scale but averted even greater losses of American, English, and Japanese lives.
• The Manhattan Project succeeded because of five specific factors: a clearly defined objective; compartmentalized tasks; positive unquestioned direction with authority delegated with responsibility; maximum use of existing agencies without empire-building; and full government backing with America’s unlimited scientific, engineering, and industrial capacity.
  • Compartmentalization had two principal advantages: simplifying security maintenance and requiring every member to attend strictly to their own work, improving over-all efficiency.
  • Groves closes with his childhood wonder about what was left for his generation to achieve after the West was won: anyone who witnessed the dawn of the Atomic Age at Alamogordo would never hold such doubts again.