“How many divisions does the pope have?” This was Stalin’s sarcastic response to Churchill’s request not to let internal developments in Poland upset relations with the pope. While Stalin’s dismissive statement suggested that the Catholic Church was an insignificant power in international affairs, he could not have been farther from the truth. Aaron Bateman writes in War on the Rock that the Holy See has played an important but understudied role in intelligence and diplomacy through its diplomatic service, which is one of the oldest in the world. The extensive presence of the Holy See’s diplomats combined with their neutrality provides them access to unique information in the far corners of the globe.