Contraspionage

Contraspionage, also known as counterespionage, is the set of activities conducted by governments, militaries, or organizations to detect, deter, and neutralize espionage by foreign intelligence services or other actors. Its primary aim is to protect sensitive information, personnel, facilities, and technological know-how that could affect national security, economic interests, or critical infrastructure.

Core functions include defensive measures such as screening and monitoring personnel for loyalty and integrity, rigorous background checks, access control, and physical and cyber security; intelligence analysis to identify espionage threats; investigation of suspected spies and informants; and measures to deceive, disrupt, or slow adversaries when legally authorized. Counterespionage also involves cooperation with law enforcement, foreign partners, and internal oversight bodies.

Legal and policy frameworks define permissible activities, balancing security needs against civil liberties. Most nations require warrants, court oversight, and parliamentary or congressional review of significant operations. The scope and methods are shaped by national laws, treaty obligations, and international norms.

Historically, counterespionage developed alongside organized intelligence services and security regimes, expanding in the modern era and adapting to new domains such as cyberspace and economic espionage. Today, the threat landscape includes state actors, nonstate actors, insider threats, and supply chain vulnerabilities, with emphasis on cyber defense, credential management, and rapid incident response.

Performance is measured by the ability to prevent breaches, identify and prosecute insiders, and disrupt enemy intelligence networks. Failures can reveal gaps in screening, information sharing, or incident response, while successful operations can deter adversaries and protect strategic assets.