A Classic in Counterintelligence-Now Back in Print Originally published in 1987, Thwarting Enemies at Home and Abroad is a unique primer that teaches the principles, strategy, and tradecraft of counterintelligence (CI). CI is often misunderstood and narrowly equated with security and catching spies, which are only part of the picture. As William R. Johnson explains, CI is the art of actively protecting secrets but also aggressively...