By the time they got to Moscow, everyone knew these rules. - Tony Mendez
During the Cold War, the CIA developed unwritten rules of engagement for their spies called The Moscow Rules. Moscow was the most dangerous and difficult destination for a spy so the spies had to have special training in clandestine operations. In his book, The Master of Disguise, Tony Mendez wrote, "Although no one had written them down, they were the precepts we all understood... By the time they got to Moscow, everyone knew these rules. They were dead simple and full of common sense...".
Here are the Moscow Rules are given as: