Numbers smaller or larger than the empirically verifiable, scholarly valid victimization range have been put forward by Japanese revisionists and the China Communist Party.
[6] Over the course of its subsequent occupation of Nanjing the Japanese Army hunted down the former Chinese soldiers within the city and in a large number of cases summarily executed them.
[7] At the same time soldiers of the Japanese Army also committed random acts of murder against civilians, and engaged in torture, rape, arson, and looting.
[9] The Nanjing Massacre was reported internationally within a week of occurring[10] and the first estimate of the full death toll was published on January 24, 1938, in the New China Daily.
[13] Timperley included a second estimate in his book published later the same year, Japanese Terror In China, which quoted "a foreign member of the University faculty" as stating that "close to 40,000 unarmed persons were killed within and near the walls of Nanking".
[14] The source of this information was Miner Searle Bates, an American resident in Nanjing who had used the burial records of the Red Swastika Society in his calculations.
[22] The International Military Tribunal of the Far East tallied up 155,000 victims of the massacre, though in their verdict against General Iwane Matsui this figure was modified somewhat to "upwards of 100,000 people".
[18][23] However, the prosecution at these trials made little effort to verify the accuracy of their death toll estimates and a considerable amount of dubious and now discredited data was accepted by both tribunals.
[12][23][24] The first historian to make an academic estimate of the death toll of the Nanjing Massacre was Tomio Hora in his 1967 book Kindai Senshi no Nazo ("Riddles of Modern War History"), who argued in favor of 200,000.
[26][27] However, emotional arguments and political interference in the debate have tended to hinder the construction of an academic consensus on the number of people killed in the atrocity.
The first type of source is oral history, but he calls this "the most problematic methodology in researching the incident" due in part to large discrepancies between the testimony of Japanese and Chinese eyewitnesses.
[21] When Yoshiaki Itakura, an independent writer who became one of the leading researchers of the Nanjing Incident,[21][32] analyzed the records of the Japanese Army, he multiplied his final tally by 0.6 in order to account for exaggeration and reached the total of 13,000 to 19,000 massacre victims.
[33] Bob Wakabayashi, a historian at York University, found out on the basis of the records of the Japanese Army alone could prove that at very least 29,240 people, or more likely 46,215 people, were massacred by the Japanese in Nanjing in the opening weeks; when considering evidence other than military records, Wakabayashi concluded the total deaths in Nanjing and its neighbouring six rural counties in a 3-month period to be "far exceed 100,000 but fall short of 200,000".
The final type of source mentioned by David Askew is data sampling, and though only one such survey of this variety was conducted, Lewis S.C. Smythe's "War Damage in the Nanking Area", it is an essential document for estimating civilian casualties of the atrocity.
[35] In addition, the total civilian population of Nanjing in December 1937 and the size of the Chinese garrison defending the city are used as a basis for calculating the death toll, though the matter is complicated due to greatly varying estimates for both of these numbers.
[34] In reference to the greatly divergent ways in which various scholars have delineated the massacre, Askew has affirmed that the debate on the death toll "is meaningless if two completely different definitions are being used".
Many historians including Kasahara view incidents like these where the Japanese fired upon retreating troops to be atrocities, whereas Hata sees them as extensions of combat and not massacres.
[43] By contrast Yoshiaki Itakura adopted an even stricter standard than Hata, advocating that only Chinese soldiers captured in uniform and then killed be included as massacre victims.
[42] He argued that Chinese soldiers who had thrown away their uniforms were legally executed because the laws of war at the time did not apply to them, though this line of reasoning is hotly disputed by other historians.
[47][48] The International Military Tribunal for the Far East stated that the massacre took place in the parts of Nanjing captured on December 13, 1937, and after and lasted until early February 1938.
This district encompassed not only the city of Nanjing proper, occupied by the Japanese from December 13, but also the six rural counties surrounding it, namely Jiangning, Lishui, Jurong, Jiangpu, Luhe, and Gaochun.
[50] In their view Honda, who had previously put forward the idea that more than 100,000 people were murdered in the city of Nanjing alone, was failing to prove his argument and therefore sought to extend the boundaries of the massacre until a larger figure for the death toll could be achieved.
[27][50] French historian Jean-Louis Margolin, for instance, has strongly criticized Honda's argument, noting that "As, in our present knowledge, it is impossible to get convincing figures for such large areas, such methods may be considered as attempts to blur hopelessly the debate.
[56] In the early 1970s, Japanese historian Hora's estimate of 200,000 massacre victims was challenged for the first time by the journalist Akira Suzuki, who suggested that "several tens of thousands" had been killed.
[1] Today most Japanese historians of the so-called "great massacre" school have reduced their death toll estimates somewhat and now advocate the figure of "100,000 plus" in contrast with the old consensus of 200,000.
[67] Joshua A. Fogel, a historian of China at York University, has decried the efforts of many Chinese to exaggerate the death toll of the atrocity and then "silence anyone who disagrees".