As the U.S. spied on the world, the CIA and NSA bickered

U.S. spy agencies were on the verge of an espionage breakthrough, closing in on the clandestine purchase of a Swiss company that could give American intelligence the ability to crack much of the world’s encrypted communications.

But the deal fell apart, done in by one of many behind-the-scenes battles between the CIA and the National Security Agency detailed in classified documents tracing one of the most remarkable intelligence operations in American history.