Inside Japan’s World War II-Era Reign Of Terror

Published December 12, 2016
Updated December 14, 2022

During World War II, Japan fought with such brutality that even today Japanese scholars and diplomats have a hard time admitting these atrocities actually happened.

Japanese War Crimes


World War II struck devastating blows everywhere it took place, but the Pacific Theater was where nations fought the longest campaigns of the war and witnessed some of the most gratuitous cruelty in history.

Between 1937 and 1945, the Empire of Japan reached out into a dozen countries with what appeared at first to be an unstoppable military machine. What that machine did after the conquest, when it had unlimited civilian lives to play with, was often so barbarous, even modern Japanese society has yet to come to grips with it.

Japanese War Crimes: The Rape of Nanking

Nanking Massacre

Wikimedia CommonsA photo taken during the Nanking Massacre.

World War II began in China. The Japanese decision to occupy and annex Manchuria in 1931 set the ball rolling for everything that followed, including the U.S.-led oil embargo that was the proximate cause of the Japanese attack on the South Pacific and the war that followed.

The first shots of this war were fired in 1937, when the Empire of Japan launched a full-scale ground invasion of China in an effort to permanently crush Chinese resistance to Japan. Within months, the Nationalist capital of Nanking fell to the Japanese, and what followed has gone down in history as one of the worst wastes of human life on record: The Rape of Nanking.

Starting around December 13, 1937, and continuing for more than six weeks, Nanking suffered as few other cities in history ever have.

The Japanese, looking at the 90,000 captives as an opportunity to train their own soldiers in brutality, transported them out of the city for executions, the more brutal the better. They marched Chinese soldiers into designated killing fields. There Japanese officers and enlisted men shot, stabbed, and beheaded the Chinese in an attempt to condition them out of having human pity for a fallen enemy.

When the supply of POWs ran thin, the Japanese turned on the city’s 600,000 civilians, whom the retreating Chinese Nationalists had prevented from fleeing. In the orgy of rape and murder that followed, which saw babies run through with bayonets and pregnant women sliced open with swords, as many as 300,000 people may have died.

Things got so bad that the 22 Westerners remaining in Nanking organized a “safety zone” near the port, under the control of a German Nazi, of all people, named John Rabe.

The Rape of Nanking was such a horrific event that Japan has yet to fully acknowledge or apologize for it. For one, official Japanese estimates place the number of dead closer to 50,000.

Even now, nearly 80 years later, this refusal to take responsibility for the first major war crime of WWII remains a stumbling block in closer diplomatic and trade relations between the two countries.

Germ Warfare

Kids 1

Xinhua/Getty Images

We’ve already brought you the story about Unit 731, the Japanese germ warfare division that worked for more than ten years to weaponize some of the worst diseases that have ever afflicted mankind, but you may not have the sheer scope of the project in view.

Founded in 1931 as a normal army medical unit, by 1935 the team was stockpiling supplies of bubonic plague, anthrax, and cholera in forms that were distressingly easy to deploy against civilians.

In just a single attack in Manchuria, the Japanese dropped aerial bombs filled with sawdust and plague-infected fleas over population centers. This was partly a terror bombing against territory that the Japanese already controlled, and partly a test of the weapon’s effectiveness.

When the bomb casings split open in the air, the fleas fell unharmed to the ground and began biting people, infecting their blood with a strain of Yersinia pestis that had been bred for greater virulence by being passed through multiple generations of Chinese and Korean prisoners.

Poring over population figures before and after the war, the Chinese government now estimates that this one attack may have killed nearly 600,000 people in the weeks following the drop. Unit 731’s other activities may have killed another half a million or so innocent people before the end of the war.

Listen above to the History Uncovered podcast, episode 51: Unit 731, also available on Apple and Spotify.


Japanese Cannibalism During World War 2

Wikimedia CommonsTwo Australian soldiers pose with human remains recovered from a Japanese encampment.

From late July to early August 1942, a full division of Japanese soldiers tried to force a difficult crossing in New Guinea’s rugged central highlands. They were opposed by a few companies of Australian regulars, who managed to not only halt the advance but to drive it back from the mountain pass. When the Australians searched the abandoned Japanese camp for signs of prisoners they had lost earlier in the fighting, what they found shocked them to their core.

From the firsthand account of Australian Corporal Bill Hedges, who was among the first into the abandoned camp:

“The Japanese had cannibalised our wounded and dead soldiers…We found them with meat stripped off their legs and half-cooked meat in the Japanese dishes…I was heartily disgusted and disappointed to see my good friend lying there, with the flesh stripped off his arms and legs; his uniform torn off him…We found dumps with rice and a lot of tinned food. So they weren’t starving and having to eat flesh because they were hungry.”

This wasn’t a one-off event. Several firsthand accounts attest to Japanese officers, sometimes very senior ones, participating in ritualized cannibalism. An Indian captive, held for the duration of the war in a series of Japanese POW camps, later attested to what he saw when an American pilot was captured. According to Havilar Changdi Ram:

“About half an hour from the time of the forced landing, the Kempai Tai beheaded the pilot. I saw this from behind a tree and watched some of the Japanese cut the flesh from his arms, legs, hips, and buttocks and carry it back to their quarters. I was so shocked at the scene and I followed the Japanese just to see what they would do with the flesh. They cut it in small pieces and fried it. Later that evening, a very senior Japanese officer, of the rank of Major-General, addressed a large number of officers. At the conclusion of his speech, a piece of fried flesh was given to all present, who ate it on the spot.”

Furthermore, we have this document captured during the war and authenticated in 1946 by the battalion commander, Major Matoba himself, regarding the treatment of eight American naval aviators captured in 1944. Incidentally, the ninth aviator – and the only man to survive the mission – was future President George H.W. Bush, who was lucky enough to be picked up by a nearby submarine before he could be captured:


I. The battalion wants to eat the flesh of the American aviator Lieutenant Hall.
II. First Lieutenant Kanamuri will see to the rationing of this flesh
III. Cadet Sakabe will attend the execution and have the liver and gall bladder removed.

Information about this practice became generally known among war crimes prosecutors after the surrender, but a sort of gentlemen’s agreement among the investigators prevented the release of these stories out of consideration of both the dead POWs’ families and the difficult reconciliation between the United States and occupied Japan.

Sex Slavery

Comfort Women

Wikimedia Commons

Though no punishments were ever handed down for crimes committed during the sack of Nanking, the Japanese High Command did take note of the international outrage and the disastrous turn of public opinion that their actions caused.

Thus, in order to prevent another mass rape, senior commanders ordered the establishment of special military brothels to cater to the men and help them keep their distance from the local women.

Female inmates of these facilities were usually drawn from occupied territories elsewhere and transported to remote locations to serve the troops. Some were lured with lies about easy work as domestic servants, while others were simply kidnapped.

Once they got to their destinations, the women were held as prisoners and could only leave with official permission. Soldiers got one day off a month to visit the “comfort women,” who were punished if they didn’t enthusiastically please their “customers.”

Comfort stations were attached to each large unit, and they moved with the front like MASH units. The captive women averaged around ages 16 to 21, though they were sometimes much younger.

As usual, sources disagree about how many victims were caught up in the program. Japanese historian Ikuhiko Hata has claimed that “only” 20,000 women were abducted in this way, while a joint project between the Chinese, Taiwanese, and Korean authorities places the number close to 400,000.

Many of the comfort women, disgraced by what had happened and suffering from various injuries and venereal diseases, chose never to return home and instead lived out their lives in whichever demolished country the defeated Japanese forces had left them in at the end of the war.

After reading about the horrific Japanese war crimes of World War II, learn about the World War II myths that people need to stop spreading. Then, have a look at the worst U.S. war crimes committed during World War II.

Richard Stockton
Richard Stockton is a freelance science and technology writer from Sacramento, California.