In 1937, Japan invaded China and captured Nanking, the capital. Hundreds of thousands of Chinese civilians were at the mercy of the invaders. What started thereafter was an inconceivable slaughter of a type so sanctioned that competitive civilian murder received news coverage back home, along with other atrocities so horrifying that a Cracked article has no place even hinting at what they are. But there was an organization called the Nanking Safety Zone, run by 22 Westerners from around the world, that was supposed to function as a haven.
One of these people would be credited with patrolling the streets and personally intervening to stop murders and prevent rapes. And rather than being some trained super soldier, he was just a guy who worked for the phone company and had been a member of the Red Cross. Soldiers naturally didn't take too well to this, and more than once Rabe found himself looking down a gun barrel. But what Rabe had to protect him was an armband with a swastika on it (oh, and he looked like an Indiana Jones villain):
Yale Divinity School Library