Debate has intensified over whether Japanese Prime Minister Sanae Takaichi will visit the war-linked Yasukuni Shrine on December 26. Takaichi is known for her right-wing historical views and has repeatedly visited the shrine while questioning established conclusions on Japan's wartime aggression.

Some analysts believe she may go ahead with the visit to signal continuity with the hardline "Abe path," as December 26 marks the date when former Prime Minister Shinzo Abe visited the shrine in 2013. Such a move would likely provoke strong protests from Asian countries, particularly from China and South Korea.

Others suggest Takaichi may skip the visit amid pressure to soften her diplomatic stance. During her leadership campaign, she claimed to work to "deepen Japan-South Korea ties," while expressing eagerness to engage in dialogue with Chinese leaders.

The Yasukuni Shrine honors 14 Class-A war criminals, including Hideki Tojo, a key figure behind Japan's wartime aggression in Asia during World War II. Any visit by Japanese leaders would seriously undermine Japan's relations with neighboring countries.

Such an act amounts to a denial of Japan's defeat in World War II and an attempt to rehabilitate militarism. It's also seen as a grave provocation to international justice and the post-war international order, while also exposing the dangerous resurgence of militarist thinking in Japan.

The debate over Takaichi's possible Yasukuni Shrine visit has once again brought Japan's wartime history into the spotlight. 

For many in Asia, the issue is not merely a diplomatic gesture or a domestic political calculation, but a question of historical memory and responsibility. To understand why such visits continue to provoke strong reactions, it's necessary to revisit the record of Japan's atrocities during WWII.

Mass killings

Historical records show that Japanese forces committed several large-scale massacres during the war, most notably in Nanjing, Singapore and Manila.

The Nanjing Massacre remains one of the most documented atrocities. After capturing the city in December 1937, Japanese troops carried out more than a month of killings, assault, arson and looting. Over 300,000 civilians and disarmed soldiers were killed.

Beyond China, Southeast Asian nations also suffered heavy losses. In Singapore, between February 18 and 25, 1942, Japanese forces launched the "Sook Ching" purge targeting the ethnic Chinese community. Estimates of the death toll vary widely – from 5,000 in Japanese records to as many as 100,000 cited by Singapore's Chinese groups.

In the Philippines, during the 1945 Battle of Manila, Japanese forces carried out widespread destruction as Allied troops advanced. More than 125,000 civilians were killed and much of the city was left in ruins.

Indiscriminate bombing and abuse of prisoners

Japan's military also conducted indiscriminate air raids across China.

After the 1931 "Mukden Incident," Japanese forces bombed civilian areas in Jinzhou, an early example of targeting populated cities. From 1937 onwards, major cities including Shanghai, Nanjing, Chongqing, Chengdu, Lanzhou, Xi'an and Kunming were repeatedly bombed. In 1939 alone, more than 2,600 air raids were recorded, resulting in tens of thousands of civilian casualties. The 1941 Chongqing tunnel disaster, caused by Japanese bombing, led to more than 1,200 deaths.

Japan's abuse of prisoners of war (POWs) is also well documented. During the Bataan Death March in 1942, approximately 75,000 American and Filipino POWs were forced by Japanese troops to march 105 kilometers to prison camps. Over 15,000 POWs died along the way due to injury, exhaustion and the brutality of their captors.

Chemical and biological warfare

Despite international prohibitions, Japan developed specialized units for chemical warfare and used chemical agents repeatedly in China. Archival documents by Japanese military detail at least 56 instances of chemical attacks between 1937 and 1942. For example, in May 1942, Japanese troops released poison gas into underground shelters where civilians were hiding in a village in north China's Hebei Province, killing more than 800 people.

At the same time, the Japanese army also conducted biological warfare and carried out human experimentation. According to Chen Zhiyuan, a history professor at the Hunan University of Arts and Science, Japan's Unit 1855 conducted more than 70 biological attacks in northern China between 1938 and 1944, causing the deaths of hundreds of thousands of Chinese civilians and soldiers through disease.

Unit 731, based in the Pingfang district of Harbin, carried out extensive human experiments, including biological infection, freezing and pressure tests. During the 1949 Khabarovsk war crimes trials, Kiyoshi Kawashima, who served as the director of the bacterial production department under Unit 731, admitted that between 1941 and the end of the war, Unit 731 used between 400 and 600 people each year as victims in its experiments.

Sexual slavery and forced labor

Meanwhile, Japan implemented a large-scale system of military sexual slavery, often referred to as the "comfort women" system. Women across Asia were abducted, deceived or coerced into sexual servitude. Official South Korean records estimate that between 80,000 and 160,000 women from the Korean Peninsula were forced into this system. Research from Shanghai Normal University indicates that more than 200,000 Chinese women were also victimized.

During the war, Japan also forcibly mobilized millions of laborers from China and other Asian countries. Civilians and POWs were sent to mines, railways and military construction sites under harsh conditions. The construction of the Thailand–Myanmar Railway alone resulted in the deaths of more than 100,000 Southeast Asian laborers and 10,000 Allied POWs due to abuse, overwork and disease. Official data shows that between 1935 and August 1945, Japan conscripted more than 15 million Chinese laborers and nearly 29 percent died due to severe conditions.

From mass killings to indiscriminate bombings, and from biological warfare to forced labor and sexual slavery, the historical record leaves no doubt about the scale and brutality of Japan's wartime atrocities. Yet even today, Japanese right-wing politicians persist in downplaying or outright denying these crimes.

As China's Foreign Ministry has emphasized, Japan cannot escape the shadow of its past through provocation or rhetorical posturing. Instead, Japan must deeply reflect on its historical responsibilities, sincerely learn from the lessons, and take concrete actions to earn the trust of its Asian neighbors.

Read more:

Remembering history: Over 300,000 Chinese killed in Nanjing Massacre by invading Japanese forces

Remembering history: The tragedy of 400,000 WWII 'comfort women'

Remembering history: When will Japan dispose its abandoned chemical weapons in China?

Remembering history: Honoring international friends who stood up for Nanjing