John Rabe was a practical and simple man. He was interested in politics, but to the extent of German commerce in China and German foreign policy in Asia. Rabe lived in China for thirty years and only visited Germany twice, both briefly. In 1930, he became the director of the Siemens, a German company that built the Nanking’s telephone system and supplied the hospitals with equipment. Rabe was known for his humor and strong character and was admired by his love for his Chinese neighbors whom he rescued and protected during the Nanking massacre. Rabe and many of his American friends built the Safety Zone in Nanking for over 250,000 Chinese. During that time, he managed to keep a diary of all the events going on until March 1938 when he returned back to Germany to report his experience in Nanking.

On 28 February Rabe leaves Nanking, traveling to Shanghai then on to Germany, where he reports to the government and people about the events in China. He presents lectures in Berlin, showing photographs, reports and an amateur film of the Japanese violence. He also writes to Hitler asking him to use his influence to persuade the Japanese to end the atrocities, Rabe is arrested and interrogated by the Gestapo (secret state police) for three days. After he is freed, Rabe is forced to be silent about the Nanking massacre. 

Here in his diary, Rabe write about committee leader’s struggle to fend off Japanese from women and children in the safety zone.
  
          "You would have thought it impossible, but the raping of women even occurred right in the middle of the women's camp in our zone, which held between 5,000 and 10,000 women. We few foreigners couldn't be at all places all the time in order to protect against these atrocities. One was powerless against these monsters who were armed to the teeth and who shot down anyone who tried to defend themselves. They only had respect for us foreigners - but nearly every one of us was close to being killed dozens of times. We asked ourselves mutually, 'How much longer can we maintain this 'bluff'?'" (moreorless)

Often times, Rabe had to use his Nazi status to save his life by showing his swastika armband.

     December 19, 1937, Rabe writes, "Six Japanese climbed over my garden wall and attempted to open the gates from the inside. When I arrive and shine my flashlight in the face of one of the bandits, he reaches for his pistol, but his hand drops quickly enough when I yell at him and hold my swastika armband under his nose. Then, on my orders, all six scramble back over the wall. My gates will never be opened to riffraff like that. (Woods, 82)

     December 24, 1937, he writes, "I have had to look at so many corpses over the last few weeks that I can keep my nerves in check even when viewing these horrible cases. It really doesn't leave you in a 'Christmas' mood; but I wanted to see these atrocities with my own eyes, so that I can speak as an eyewitness later.  A man cannot be silent about this kind of cruelty!" (Woods, 92)

References:

Harris, Bruce. "John Rabe." moreorless: heroes & killers of the 20th Century. 18 July 2007. 22 Jul 2007 <http://www.moreorless.au.com/heroes/rabe.html>.

"The Establishment of the Nanjing International Safety Zone." Nanjing 1937: TheMemorial Hall of the victims in Nanking Massacre by Japanese Invader. 2005. Shuiximen Street Nanjing Chinese. 21 Jul 2007
<http://www.nj1937.org/english/massacre_2.asp>.

Woods, John E. The Good Man of Nanking: Diaries of John Rabe . New York: Alfred A. Knoff, Inc., 1998.