The CIA thought it had thoroughly penetrated Cuban intelligence, with scores of agents and informants in Havana, until one day a Cuban officer walked into the U.S. Embassy in Vienna and broke the news—the agents were actually double agents. James Olson was the CIA station chief in Vienna at the time. He would go on to serve as the agency’s head of counterintelligence.   Check out I Spy's merch by going to https://store.dftba.com/collections/i-spy Save 15% on FP subscriptions. Visit https://foreignpolicy.com/subscribe/ and enter code ISPY at checkout to claim this offer.