Operation Paperclip: The Secret Intelligence Program That Brought Nazi Scientists to America is a 2014 nonfiction book by investigative journalist Annie Jacobsen. The book documents the titular US government initiative to recruit German scientific and technical experts following World War II. Jacobsen follows more than a dozen key figures—including rocket scientist Wernher von Braun and biological weapons expert Kurt Blome—from their roles in the Third Reich to their postwar employment in the United States, revealing how their complicity in war crimes was deliberately concealed for national security. The book explores themes of The Moral Compromise of National Security, The Corruption of Science for Ideological Ends, and Secrecy as an Instrument of State Power.

Operation Paperclip was a national bestseller and a finalist for the 2015 Pulitzer Prize in History. Jacobsen is an author known for her work on US government secrecy and national security, including her previous bestseller Area 51: An Uncensored History of America’s Top Secret Military Base (2011).

This guide refers to the 2015 paperback edition published by Back Bay Books.

Content Warning: The source material and guide feature depictions of racism, religious discrimination, sexual violence and/or harassment, rape, ableism, child death, animal cruelty and/or death, graphic violence, illness or death, suicide, physical abuse, and emotional abuse.

Summary

In November 1944, Samuel Goudsmit, the scientific director of a top-secret Allied intelligence mission called Operation Alsos, discovered documents in Strasbourg, France, which revealed that Nazi doctors were conducting medical experiments on concentration camp prisoners. A letter from virologist Dr. Eugen Haagen requested healthy prisoners for experiments, leading Goudsmit to conclude that the Nazis were developing vaccines for biological weapons. The documents named two key figures: Dr. Kurt Blome, head of the Reich’s biological weapons program, and Surgeon General Walter Schreiber, head of its vaccine program. Meanwhile, Germany’s V-2 rocket program, led by Major General Walter Dornberger and physicist Wernher von Braun, was celebrated by armaments minister Albert Speer. The V-2s, built by enslaved laborers in extremely traumatic conditions at the underground Mittelwerk factory near Nordhausen, were launched at Allied targets. Evidence showed von Braun’s direct involvement in procuring enslaved laborers from Buchenwald. As the war neared its end, Hitler issued a scorched-earth policy, and von Braun instructed his aides to hide classified V-2 documents to use as a bargaining chip with the Allies.

As the Red Army advanced in early 1945, Nazi officials began destroying evidence of their crimes. Dr. Otto Ambros, a chemist for the conglomerate IG Farben, oversaw the destruction of documents at the company’s synthetic rubber factory at Auschwitz before the camp was evacuated. At another secret IG Farben facility in Dyhernfurth mass-produced the nerve agent tabun. Ambros and SS-Brigadeführer Dr. Walter Schieber were central to this chemical weapons program.

Following the Allied invasion of Germany, intelligence units including Alsos and the Combined Intelligence Objectives Subcommittee (CIOS) began a competitive hunt for Nazi scientists. A major breakthrough occurred with the discovery of the “Osenberg List,” a comprehensive directory of 15,000 German scientists and 1,400 research facilities. As Allied forces advanced, they liberated key sites. At Nordhausen, they uncovered the horrors of the V-2 forced labor camp and found a telephone list that implicated general manager Georg Rickhey and operations director Arthur Rudolph. At Geraberg, they found an abandoned biological weapons lab linked to Dr. Kurt Blome. At Völkenrode, Colonel Donald L. Putt discovered the advanced Hermann Göring Aeronautical Research Center and proposed bringing its scientists to America.

With Germany’s surrender, key Nazi figures were captured. Dr. Walter Schreiber was taken by the Soviets in Berlin. Wernher von Braun and his group of rocket scientists surrendered to American forces. The CIOS team captured IG Farben CEO Hermann Schmitz and discovered a photo album documenting the construction of the IG Auschwitz factory. Dr. Otto Ambros was found in Gendorf, initially deceiving soldiers by posing as a simple chemist. Dr. Kurt Blome was arrested but gave an evasive interrogation. Georg Rickhey was captured and offered a job in exchange for information on underground factories. Albert Speer was arrested, while Heinrich Himmler died by suicide after his capture. In the immediate aftermath of the war, there was no official US policy on what to do with these captured scientists.

In the absence of a formal policy, US military branches raced to exploit German science before the Soviets could. Major Robert Staver of Special Mission V-2 secured 100 V-2 rockets and 14 tons of technical documents from a mine near Nordhausen before the area was transferred to Soviet control. Staver urged the Pentagon to recruit the German rocket scientists to aid in the war against Japan. The first Nazi scientists, including guided-missile expert Dr. Herbert Wagner, were secretly brought to the United States.

Simultaneously, Colonel Harry Armstrong of the US Army Air Forces began recruiting Luftwaffe doctors, focusing on the prominent aviation medicine expert Dr. Hubertus Strughold. In a parallel investigation, Dr. Leopold Alexander, a Jewish-American war crimes investigator, uncovered evidence of medical murders at Dachau. He discovered Himmler’s secret files, which contained photographic proof of lethal experiments conducted by Strughold’s close colleagues, Dr. Siegfried Ruff and Dr. Theodor Benzinger. Unaware of these crimes, other Allied intelligence officers were recruiting these same doctors. The US Army Air Forces established the secret Aero Medical Center in Heidelberg, where it employed 58 former Nazi doctors, several of whom had been implicated in war crimes.

The State-War-Navy Coordinating Committee (SWNCC) intensified its debate over the scientist program, with Assistant Secretary of War John J. McCloy playing a central role. At the secret “Ashcan” interrogation center, US intelligence officer John Dolibois questioned top Nazi war criminals like Hermann Göring and Albert Speer. The “Ambros Affair” unfolded when Lt. Col. Philip Tarr of the US Chemical Warfare Service sheltered Otto Ambros from arrest to exploit his knowledge, even arranging a meeting with a representative from Dow Chemical. Meanwhile, Tarr’s British CIOS partner, Major Edmund Tilley, conducted a separate investigation that eventually led to the discovery of hidden documents proving Ambros’s guilt. On July 6, 1945, the Joint Chiefs of Staff officially approved the recruitment program, codenamed Operation Overcast. The first group of rocket scientists was brought to the US, while the trial of major war criminals began at Nuremberg, creating a stark contrast between the Nazis being hanged and those being hired.

The Joint Intelligence Objectives Agency (JIOA) took control of the program, escalating recruitment due to the growing Soviet threat. The program was renamed Operation Paperclip after a system devised to attach a paperclip to the files of ardent Nazis to bypass State Department scrutiny. The Joint Intelligence Committee’s (JIC) prediction of “total war” with the Soviets provided further justification. In August 1946, the Soviets produced a surprise witness at the Nuremberg trials: Major General Dr. Walter Schreiber. His testimony implicated Dr. Kurt Blome in biological weapons research on humans, leading to Blome’s arrest and indictment.

The press exposed Operation Paperclip, leading to public backlash from figures like Albert Einstein. The Georg Rickhey affair further damaged the program’s reputation when he was sent back to Germany to stand trial for war crimes. He was acquitted and the US Army sealed the trial records. The Nuremberg doctors’ trial began, with several defendants having been recently employed by the US Army in Heidelberg. While others were convicted, Blome, Ruff, and another Paperclip recruit, Konrad Schäfer, were acquitted, making them available for post-trial recruitment.

As the Cold War intensified, the Chemical Corps recruited chemist Fritz Hoffmann to work on nerve agents at Edgewood Arsenal, which led to research on incapacitating agents like LSD under the new concept of “psychochemical warfare.” Camp Detrick expanded its biological weapons research and consulted with the acquitted Kurt Blome. In Heidelberg, Brigadier General Charles Loucks formed a secret working group with ex-Nazi chemists, including Walter Schieber, to obtain the formula for sarin. The CIA became heavily involved, establishing the Camp King interrogation center as a black site for mind-control programs. In 1948, Walter Schreiber mysteriously “escaped” from Soviet custody and was recruited into Operation Paperclip, eventually becoming the post physician at Camp King. Meanwhile, John J. McCloy, now US High Commissioner for Germany, began granting clemency to convicted war criminals and the Korean War triggered “Accelerated Paperclip” to evacuate more scientists, including Otto Ambros, who was placed on the target list while still in prison.

In 1951, Dr. Leopold Alexander discovered that Walter Schreiber was working for the US Air Force in Texas and alerted the press. Ravensbrück survivor Janina Iwanska identified Schreiber as having been present during the medical experiments performed on her, sparking a public scandal. To avoid further controversy and a potential investigation into the broader Paperclip program, the US government secretly facilitated Schreiber’s relocation to Argentina.

Operation Paperclip’s legacy was complex and contradictory. President Eisenhower later warned against the influence of the “scientific-technological elite,” specifically naming Wernher von Braun. Post-war investigations revealed that some Operation Paperclip scientists, like Walter Schieber, continued their deceptive practices, working as double agents and arms dealers while on the US payroll. In 1969, President Nixon ended the US offensive biological and chemical weapons programs. The past careers of celebrity scientists like Dornberger, von Braun, and Strughold were exposed, showing how they achieved status while their Nazi pasts were whitewashed. In the 1980s, the Justice Department’s Office of Special Investigations (OSI) began to uncover the truth, leading to Arthur Rudolph renouncing his US citizenship to avoid prosecution for his role at the Mittelwerk. The post-prison career of Otto Ambros was also revealed, including his work for the US Department of Energy and his connection to the thalidomide tragedy. The book concludes by reflecting on the enduring moral questions of the program, the ongoing process of declassification, and the contrast between the celebrated legacies of the scientists and the lasting trauma of their victims.