What do the KGB, David Irving, and Daniel Goldhagen have in common?

You can find the answer here. An excerpt:

Like many Jews in post-war America, "I grew up in a Conservative home hating Pius," he says. But when Krupp received a call from author Dan Kurzman, the tables began to turn.Kurzman needed help with research for his book, A Special Mission: Hitler's Secret Plot to Seize the Vatican and Kidnap Pope Pius XII. Krupp contacted an archivist at Yad VaShem, who wasn't aware of the story; nor was the Israeli ambassador to the Vatican. "I thought, 'Something's wrong here,'" says Krupp, who was eventually put in touch with a nun in New Jersey. "She told me, 'Not only was he not a Nazi collaborator or an antisemite, but he did more to save more Jews than anyone else,'" Krupp recalls.