Tokyo Must Address the Actions of Its Wartime ‘Killing Machine’

Rabbi Abraham Cooper is the associate dean of the Simon Wiesenthal Center

What if there was no Nazi hunter like Simon Wiesenthal to pursue the perpetrators of genocide? What if the U.S. bartered Auschwitz doctor Josef Mengeles’ freedom in return for the results of his horrific experiments? What if postwar Germany had installed top Nazi doctors in the National Institutes of Health or as deans in leading medical schools or as surgeons general of the new German defense forces? Impossible, you say? A second-rate script or a third-rate novel? No, I have just described what happened in postwar Japan to a cadre of unrepentant criminals whose deeds matched their Nazi soul mates in cruelty and depravity. And incredibly, one of the surviving war criminals recently invited me to his home to gloat about his role.

Meet Toshimo Mizobuchi, an energetic 76-year-old, who lives near Kobe where he granted me a 2 1/2-hour interview. Still vigorous, he is organizing this year’s reunion of several hundred surviving veterans of the Japanese Army’s Unit 731, which conducted Japan’s not-so-secret chemical-biological warfare operation in Manchuria before and during World War II.

Deliberately infected with plague, anthrax, cholera and other pathogens, an estimated 10,000 Chinese civilians and allied prisoners of war were made into human guinea pigs by Unit 731. They were vivisected without anesthesia and then dispatched by lethal injection. Other experiments involved tying victims to stakes and bombarding them with shrapnel laced with gangrene; inserting them in pressure chambers to see how much their bodies could take before their eyes popped; and exposing them, periodically drenched in water, to subzero weather to determine their susceptibility to frostbite. Three large incinerators disposed of the corpses, which burned quickly because the internal organs had been removed.

Beyond the torture chambers of Unit 731, which occupied a six-square-kilometer base that rivaled Auschwitz-Birkenau in size, the Japanese Army conducted germ-warfare field tests not only against nearby Chinese and Russian territory but as far away as Burma, Thailand and Indonesia. The death toll may have run as high as 200,000.


A training officer, my solicitous host Mizobuchi was a mere cog in a killing machine staffed by 3,000 medical research personnel, many recruited from Japan’s top institutions of higher learning. The mastermind of it all was Gen. Shiro Ishii, a physician who combined a flair for organization with the sadism of Mengele. American occupation authorities in Japan, who after the war gave Ishii immunity from war crimes prosecution, were astounded by the scope of an operation that, in addition to producing lethal pathogens, manufactured 20 million doses of vaccine each year at just one facility.

Ishii also shared the Nazi penchant for euphemism. His murderous operation was designated the Water Purification Bureau. And while Mengele called his gruesome experiments Artzvorstellern or “medical checkups,” Ishii designated his victims as muralas or “logs,” a grim joke that originated when the Japanese told the local Manchurians that the Unit 731 facility was being built as “a lumber mill.”

A half-century later, Unit 731’s victims are still nothing more than “logs” to Mizobuchi.

Assigned to Unit 731 in January 1943, he first learned of its treatment of experimental subjects when be was told the meaning of the “white smoke coming from the chimneys.” Later, he became an instructor who taught new recruits without personally participating--or so he claims--in torture. Mizobuchi also disclaims responsibility for the liquidation of the camp in 1945 of all remaining 400 prisoners by “volunteers” who reported to him.


Mizobuchi then described the lessons he learned and imparted to his students that were based on human experimentation and included “what happened when a human being did not have water for a week. He would go insane. With water but without food, a person could last 50 to 60 days.” When I asked whether he had any regrets about what was done to the prisoners, Mizobuchi almost jumped out of his chair. “No” he insisted defiantly, “the logs were not considered to be human. They were either spies or conspirators already sentenced to death. So now they died a second time. We just executed the death sentence.”

Mizobuchi even detailed Japan’s aborted plan to unleash germ warfare against American troops on Saipan in June 1944. He also participated in July 1945, in training kamikaze pilots for Operation Cherry Blossoms at Night. This was to involve five submarines, each carrying two or three small aircraft with wings folded against the fuselage, to the California coast where they would attack San Diego with “plague bombs” full of infected fleas. Planning for this incredible operation only was aborted when Japan abruptly surrendered after the atomic bombing of Hiroshima and Nagasaki.

Mizobuchi has nothing but praise for Gen. Ishii of Unit 731. He considers his ultimate military superior, Gen. Hideki Tojo, “a war criminal” but only in the sense that he launched a war that he should have known Japan was not yet prepared to win.

As for himself, Mizobuchi confirmed to me that under the same circumstances, he would again be a “willing executioner” with no compunctions about his role.


While Germany has faced up to the horrors committed by its Mengeles, the time is long overdue for Japan to admit the atrocities committed by its Ishiis and Mizobuchis. For despite the efforts of Japanese activists, including a handful of repentant war criminals, today’s Japanese government continues to maintain its half century virtual blockade against telling the full historical truth to its younger generations.

The American government, however belatedly, has begun to address our own national complicity in covering up the crimes of Unit 731. The U.S. Justice Department wants to add to its “watch list” of war criminals, which currently includes 60,000 Europeans but fewer than 100 Japanese, those responsible for war crimes ranging from the Nanjing massacre to the work of Unit 731. Washington should also immediately rescind the blanket amnesty granted to these criminals.

But Japan must also awake from its self-inflicted amnesia. An international historic commission convened by Tokyo would replace revisionism and propaganda with an honest quest for history. It would also go a long way to reassure Japan’s Asian neighbors that it has learned the lessons of the past and deserves their trust.

Even professed neutral nations like Sweden and Switzerland have had the courage to take a painful look back at their World War II record; can Japan be allowed to do any less?


As Japan tries to gain permanent member status on the U.N. Security Council, the international community must insist on Tokyo assuming a moral responsibility consistent with its aspirations for international political and economic leadership. The memory of the nameless victims of Unit 731 demand no less.