Book excerpt: 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 thwarting, penetrating, and deceiving hostile intelligence organizations to neutralize or even manipulate their operations. Johnson, a career CIA intelligence officer, lucidly presents the nuts and bolts of the business of counterintelligence and the characteristics that make a good CI officer. Although written during the late Cold War, this book continues to be useful for intelligence professionals, scholars, and students because the basic principles of CI are largely timeless. General readers will enjoy the lively narrative and detailed descriptions of tradecraft that reveal the real world of intelligence and espionage. A new foreword by former CIA officer and noted author William Hood provides a contemporary perspective on this valuable book and its author.