Calder Walton is the assistant director of the Harvard Kennedy School’s Applied History Project, and director of research of its Intelligence Project. He is writing a book about British, American, and Soviet intelligence in the Cold War. Christopher Andrew is an emeritus professor of modern and contemporary history and founder of the Intelligence Seminar at Cambridge University. His books include The Secret World: A History of Intelligence and Stars and Spies: Intelligence Operations and the Entertainment Business (forthcoming in 2021, written in collaboration with Julius Green).