Sheer conjecture.
Remember -- the Italians were 95% Catholic, as were many Germans and other Europeans.
Mussolini was Italian too, you think he'd answer anything but "yes sir" if Hitler told him to level the Vatican.
Also, look at what happened in Catholic France in the eighteenth century, and in Catholic Spain and Mexico in the twentieth century. Sometimes Catholic countries are the Church's worst enemies.
So you ask a completely speculative question, and then shrug off the answer as "sheer conjecture". That's kinda funny.