Chaim spoke about this on a previous Ask JTF show. He believes that Pope Pius was complicit in the Nazi genocide of Jews and other "undesirables." Chaim said that Pope Pius could have had it stopped if he simply put his foot down, but he did not.
Also, in a more recent thread, Chaim pointed out of all the Catholics who were excommunicated for opposing various church doctrines, none of them were ever Nazis. In fact, Adolph Hitler was never excommunicated. He also said something about the Vatican helping sneak Nazis out of Germany and into South America after World War II.
These photos just show the chumminess of the German religious leaders with the Nazis, which is not good.
So suffice it to say that although the Roman Catholic Church has had a brutal history regarding Jews, we have nothing against working with righteous members who are philo-Semitic Catholics, and who are pro-Israel.