counterespionage

n.

反间谍（活动），策反；

Counterespionage
Counterespionage Techniques That Work
Counterespionage in an Insect Herbivore-Parasitoid System
US nuclear labs find counterespionage difficult
The Xenophobic Style: French Counterespionage and the Emergence of the Dreyfus Affair
The CIA's secret operations : espionage, counterespionage, and covert action
Terror and Conformity: Counterespionage Campaigns, Rectification, and Mass Movements, 1942-1943
방첩의 개념과 실제 : 대스파이 활동(Counterespionage)을 중심으로
Hitler's Secret War in South America, 1939–1947: German Military Espionage and Allied Counterespionage in Brazil
Hitler's Secret War in South America, 1939-1945: German Military Espionage and Allied Counterespionage in Brazil by Stanley E. Hilton