A Secret History of the Japanese Army

15 Aug 2025 · 10 min · 3 chapters

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In short

The episode is about Japan’s WWII biological warfare program, especially Unit 731, and the U.S. role in shielding its data. It also briefly covers a separate U.S. human-rights reporting controversy.

Guests

Hideo Shimizu, 95, a former Unit 731 youth corps member who arrived at headquarters in China in 1945 and later apologized in China; Hideaki Hara, a former school teacher who supports Shimizu; Katsutoshi Takegami, 77, who researched his father’s service after finding photos showing Unit 1644; Lu Jing, a Nanjing University historian; Barack Kushner, Cambridge East Asian history professor.

Key claims

experiments used “maruta” (treated as logs), including live dissection and germ warfare; Unit 731 killed about 3,000; evidence destruction followed the war; the U.S. granted Unit 731 immunity, tied to Cold War secrecy; Unit 1644 was framed as “anti-epidemic” while also spreading disease.

Notable examples

a jarred specimen of a whole female body with a fetus; Japan rescheduling a China movie premiere referencing Unit 731; Japan’s National Archives releasing Unit 1644 rosters.

Written by AI. May contain mistakes. Listen to the episode to check what was said.

Chapters

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The Infamous Unit 731

0:45 to 4:19

Exploring the brutal experiments conducted by Japan's Unit 731 during WWII.

“And a warning, this piece contains language that may make some listeners uncomfortable.”

U.S. Immunity and Cold War Politics

4:19 to 5:26

Discussion on the U.S. granting immunity to Unit 731 members and its implications.

“Accused Tojo Hideki, on the counts of the indictment on which you have been convicted, the International Military Tribunal for the Far East sentences you to death by hanging.”

Changes in U.S. Human Rights Approach

5:26 to 9:35

Examining the Trump administration's shift in focus on human rights issues.

“kept the details of Unit 731 and its immunity deal secret for decades.”
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Transcript

Automatic transcript. May contain errors.

0:00Today on State of the World, a secret history of the Japanese army of a World War II-era biological warfare unit.

0:12You're listening to State of the World from NPR, the day's most vital international stories, up close where they're happening. It's Friday, August 15th. I'm Christine Arismeth. It was 80 years ago today that Japan's surrender was announced, ending World War II. A formal surrender would follow. Even as the conflict fades from living memory, wartime disputes live on in Asia, and wartime secrets continue to be unearthed. NPR's Anthony Kuhn reports on one episode in which the U.S. played a controversial role. And a warning, this piece contains language that may make some listeners uncomfortable.

0:58One of the most anticipated movies of this summer in China was scheduled to premiere on July 31st. That date is a reference to Unit 731, a once-secret biological warfare unit of the Japanese Imperial Army. It's infamous for conducting brutal experiments, such as dissecting live prisoners, some without anesthesia, and conducting germ warfare. Authorities rescheduled the movie premiere for next month without explanation. Unit 731 members were instructed to keep the unit secret. We visited one former member in central Japan's Nagano Prefecture. Hideo Shimizu is now 95. He joined Unit 731's youth corps at age 14.

1:42He arrived at unit headquarters in northeast China in 1945, five months before the end of the war. He remembers entering a room one day filled with specimens of human organs in glass jars. The most shocking thing for me was a specimen of a whole female body with a fetus in its womb. Unit 731 doctors called the people they experimented on maruta, or logs, in other words, not human. The Japanese government has admitted the unit's existence, but has not apologized for its actions. As the war ended, the unit began destroying evidence and witnesses. Shimizu points at a map showing the buildings that held the prisoners.

2:27I did not see any of the Maruta alive. All I did was collect their bones and put them in a bag. Unit 731 is estimated to have killed around 3 ,000 people. Last year, Shimizu traveled to China to apologize. He's faced criticism in Japan for speaking out. Others support him, like Hideaki Hara, a former school teacher in Nagano. When we talk about the war, it's easier to talk about ourselves as victims, such as of the atomic bombings. But our role as perpetrators is not often discussed. People don't want to talk about it. But 77-year-old Katsutoshi Takegami wants to talk. Several years ago, in his home in Nagano Prefecture, he discovered a trunk that belonged to his father.

3:11It contained photos that showed his father serving in Unit 1644, another part of Japan's bio-warfare program. Since then, Takagami has been researching his father's military service. If you kill a lot of people, you become a hero and get promoted. I was worried that my father had done something bad, and that's how I got started investigating this thing. In May, at the request of researchers, Japan's National Archives made public Unit 1644's personnel rosters. It's a windfall for researchers like Nanjing University historian Lu Jing. She says it was officially known as an anti-epidemic and water supply unit.

3:51They tried to adapt to local conditions, solving problems in the environment they were fighting in and using them against their enemy. In other words, they protected their troops from diseases while spreading them among their enemies. After the war, an international tribunal similar to the Nuremberg trials in Germany sentenced seven Japanese officials to death for war crimes, including the wartime prime minister. Chief Justice William Webb handed down the sentence on November 12, 1948. Accused Tojo Hideki, on the counts of the indictment on which you have been convicted, the International Military Tribunal for the Far East sentences you to death by hanging.

4:33But the U.S. gave members of Japan's Unit 731 immunity from prosecution, says Barack Kushner, a professor of East Asian history at Cambridge University. It is a lapse of justice to the highest degree. And of course, the reason it's kept out mainly is Americans want the data for themselves and they don't want the Soviets to get it. Kushner argues that the Japanese experiment data was worthless because it was obtained essentially through torture. America has a certain ideal about itself and the way in which it does things. But at the end of the day, it seems to behave in a way that corresponds to precisely what other militaries are doing at the same time, which is thinking about its own self-interest and thinking about national security and justice be damned.

5:20Cold War politics, Kushner says, limited efforts to achieve justice for World War II's atrocities. The U.S. kept the details of Unit 731 and its immunity deal secret for decades. Anthony Kuhn, NPR News, Tokyo.

5:38We turn now to an issue in the U.S. that has human rights activists alarmed. The Trump administration is changing America's focus on its approach to human rights a long-time bipartisan issue. In its latest country reports, the State Department downplayed women's rights and LGBTQ plus rights while focusing more on free speech for conservatives in Europe. As NPR's Michelle Kellerman reports, the State Department is being reorganized to reflect this change in priorities, too. Desiree Cormier-Smith was the one and so far only Special Envoy for Racial Equity and Justice. She was bracing for big changes to the annual human rights reports on countries around the world, but it was worse than she imagined.

6:25It just boggles my mind how awful these reports are in their attempted erasure of anyone who is not white, Christian, male or straight. The State Department not only deleted sections in the country reports that focused on women, minorities, and LGBTQ plus people, it's also closed offices on these issues. There's one new office of natural rights, which the State Department says is based on Western traditions and America's founding documents. That concerns Cormier Smith, who has joined with other former special envoys who saw their offices closed in the reorganization. I think the signals are quite loud and quite clear of who they value and who they don't.

7:10Officials say the reforms are part of Secretary of State Marco Rubio's efforts to streamline a bureaucracy that they say has become bloated in the post-Cold War era. They say the regional bureaus can cover these issues just as well as a special envoy. They also have a new area of focus on allies in Europe. Some of those countries are fighting Russian disinformation and hate speech. but Trump's State Department spokesperson, Tammy Bruce, calls it censorship. No matter, really, how disagreeable someone's speech may be, criminalizing it or silencing it by force only serves as a catalyst for further hatred, suppression, and polarization.

7:50As for the human rights reports, Bruce said they had to be rewritten to make it easier to read and more focused on Trump's priorities. If we weren't going to release something compiled and written by the previous administration, It needed to change based on the point of view and the vision of the Trump administration. And so those changes were made. Jessica Stern, who was the Biden administration's envoy for LGBTQ plus people, was shocked to see all of the sections that she worked on deleted. She says there are real risks to activists who helped U.S. embassies compile the reports and asylum seekers who won't be able to rely on these documents for their court cases.

8:30My assumption, unfortunately, is that more LGBTQI people that are fleeing violence and seeking asylum in the U.S. are going to have their claims denied. Stern says the administration has been using marginalized and vulnerable groups to justify other big changes in America's foreign policy institutions. So, for example, we saw in the takedown of USAID that they repeatedly cited a couple of tiny grants to support LGBTQI programming that had no impact whatsoever on the bottom line. The U.S. Agency for International Development has been dismantled and the State Department has taken over what remains of U.S.

9:12foreign aid. Republicans who supported the move often cite what they see as egregious examples of waste, mostly programs that supported LGBTQ plus communities abroad. Michelle Kellerman, NPR News, the State Department.

9:31That's the State of the World from NPR. Thanks for listening.

From the publisher

On the 80th anniversary of Japan’s surrender in WWII, the legacy of a biological warfare unit still haunts. And human rights activists are alarmed by the Trump administration’s changing focus. 

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