A little more about Pope Benedict’s “Nazi past.” When membership in an immoral political party is compulsory, and you are not obliged to commit any heinous acts, then I do not think joining it is morally wrong. Since everyone living under the party’s regime understands the rules, and that membership is not a personal statement backing the party’s crimes, they cannot possibly be scandalized.
A personal anecdote: When I was in Iraq, one of our translators invited us to dinner with his family. His brother was a teenager who loved everything about America, which he had learned about on the Internet. He loved our laws, our music and movies, our guns, and our freedoms. He completely hated the Ba’athist Party, but to go to high school, he had to join it. The brother didn’t have to gas Kurds or feed women into industrial shredders, he just had to go through the motions. I don’t think he did anything wrong, either.