Thread by @_HistoryNerd

The Nazis weren’t history’s only monsters.

Japan’s Unit 731 froze prisoners alive, dissected children without anesthesia, and unleashed plague bombs on cities.

And one man, Shirō Ishii, led it all.

Here’s the forgotten horror of WWII:

Shirō Ishii was born in 1892 into a wealthy Japanese noble family.

After earning his PhD in microbiology, he quickly climbed the ranks in Japan’s Imperial Army Medical Corps.

But Ishii wasn’t just interested in medicine, he wanted power.

In 1925, the Geneva Convention banned biological weapons.

But Ishii saw that as proof of their effectiveness.

He founded Unit 731 with military support, a top-secret facility disguised as a disease prevention research lab.

In reality, it was a human slaughterhouse.

Located in Harbin, Manchuria, Unit 731 was one of the most brutal death factories of World War II.

The victims?

Chinese civilians, Allied POWs (including Americans), Koreans, Mongolians, and even women and children.

Here are just some of the horrors that took place inside:

1. Vivisections Without Anesthesia

Prisoners were dissected alive so doctors could study the effects of diseases on organs.

No painkillers were used.

Victims were infected with deadly diseases like the plague, syphilis, and anthrax.

Once the disease spreads, doctors cut them open while still alive to examine its effects in real-time.

Organs were removed one by one while the prisoners were still conscious.

After the experiments, the victims were either burned, buried, or dissected for further study.

2. Frostbite Experiments

Japanese soldiers needed to fight in cold climates, so Ishii sought to study the extent to which a human body could endure freezing temperatures.

Prisoners had their arms and legs exposed to freezing temperatures until their flesh turned black.

3. Weaponizing the Plague

Ishii wanted to turn diseases into weapons of mass destruction.

Bubonic plague-infected fleas were dropped from planes over Chinese villages.

Poisoned food and water supplies were given to civilians to test how fast diseases spread.

Rats infected with the plague were released into cities.

Over 500,000 people died from these biological attacks.

4. Disease-Infected Prostitution Rings

Unit 731 wanted to study how sexually transmitted diseases spread in real-time.

Women were forced to have sex with infected men.

Some were repeatedly raped to track how diseases spread across multiple pregnancies.

5. Biological Weapon Testing on Entire Cities

Ishii wanted to test bioweapons on a massive scale, so Japan targeted entire Chinese towns.

Planes dropped cholera and typhoid bombs on unsuspecting villages.

Water supplies were contaminated with anthrax, dysentery, and plague bacteria.

Food was laced with disease and given to starving civilians.

Entire towns were wiped out within days.

In 1945, Japan planned "Operation Cherry Blossoms at Night", a biological attack on the U.S.

Ishii planned to load plague-infected fleas onto submarines.

These submarines would launch planes over San Diego and release the fleas, causing an outbreak of bubonic plague in the U.S.

When Japan surrendered in 1945, Ishii knew he had to cover his tracks.

He burned down Unit 731, killed the remaining prisoners, and destroyed all evidence.

The Soviet Union wanted to put him on trial for war crimes.

But the U.S. made a deal with him instead.

In exchange for his research, the U.S. granted him full immunity.

The U.S. government hid all evidence of Unit 731’s crimes, and he never spent a day in prison.

Ishii lived a quiet, comfortable life in Japan.

He died of cancer in 1959, never facing justice.

Unlike Nazi war criminals, who were tried at the Nuremberg Trials, Ishii and his men were protected.

Some former Unit 731 scientists even helped develop Japan’s modern pharmaceutical industry.

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