John Rabe was the liaison between Imperial Japan and Nazi Germany.
He was so appalled by what he saw during the Rape of Nanking he wrote a personal letter to Adolf Hitler appealing for clemency on humanitarian grounds.
He got arrested by the Gestapo for his trouble..
Watched a documentary the other day about Victor Sorge, the master Soviet spy who was eventually executed by the Japanese, but he was the one who warned Stalin that the Nazis were about to attack the Soviet Union.