All warfare is based on deception. There is no place where espionage is not used. Offer the enemy bait to lure him. - Sun-Tzu
Certain backward areas have advanced, and various devices always in some way connected with warfare and police espionage have developed, but experiment and invention have largely stopped. - George Orwell
Not every story has explosions and car chases. That's why they have nudity and espionage.
Li, a willowy manboy with a shock of black hair atop a mouthful of bad teeth was the brother-in-law he had introduced to industrial espionage several years back. Rong often regretted that. - Michael Benzehabe
Cyber attacks are not what makes the cool war 'cool.' As a strategic matter, they do not differ fundamentally from older tools of espionage and sabotage - Noah Feldman