Rabe's diaries were made known and quoted by author Iris Chang during the research for her book, The Rape of Nanking;[1] they were subsequently translated from German to English by John E. Woods and published in the United States in 1998.

The diaries of Rabe could only provide witnesses of a small corner of the Nanjing Massacre, because of the limitation of his activity in the safe zone.

"[3] While, on the next day of the fall of Nanjing, Rabe handed a letter of thanks to the Japanese army commander concerning that the people in the Safety Zone could stay without one fire and were all safe.

The following is an excerpt: "In other words, on the 13th when your troops entered the city, we had nearly all the civilian population gathered in a Zone in which there had been very little destruction by stray shells and no looting by soldiers even in full retreat.

... All 27 Occidentals in the city at that time and our Chinese population were totally surprised by the reign of robbery, raping and killing initiated by your soldiers on the 14th.

"[5] Having received no answer to his request, Rabe wrote again to Fukui the following day, this time in an even more desperate tone: "We are sorry to trouble you again but the sufferings and needs of the 200 000 civilians for whom we are trying to care make it urgent that we try to secure action from your military authorities to stop the present disorder among Japanese soldiers wandering through the Safety Zone.

[...] The second man in our Housing Commission had to see two women in his family at 23 Hankow Road raped last night at supper time by Japanese soldiers.

Our associate food commissioner, Mr. Sone, has to convey trucks with rice and leave 2,500 people in families at his Nanking Theological Seminary to look for themselves.

'"[7] John Rabe gave a series of lectures in Germany after he came back to Berlin on 15 April 1938, in which he said, "We Europeans put the number [of civilian casualties] at about 50,000 to 60,000.