" shutting down an operation was at least as delicate as initiating one, for it required coming up with just the right combination of rewards and threats to ensure a cashiered agent’s silence. Far easier, in fact, to simply let a dead-end mission limp along indefinitely. “They should have made it a rule at the outset,” Sichel said, “that if you propose an operation, you also have to explain how you’re going to shut it down.” He gave a sardonic smile. “Oh, how we envied the Russians; when they were done with their agents, they could just shoot them. "

― Scott Anderson , The Quiet Americans: Four CIA Spies at the Dawn of the Cold War—A Tragedy in Three Acts