Which agency is primarily responsible for foreign SIGINT?

• A. Central Intelligence Agency
• B. National Security Agency
• C. Department of Homeland Security
• D. Federal Bureau of Investigation

Answer: (B)

Signals intelligence, or SIGINT, involves intercepting and analyzing electronic signals to gain information. When the focus is on targets outside the United States, that responsibility falls to the National Security Agency. The NSA operates under the Department of Defense and specializes in collecting, decoding, and exploiting foreign signals and cryptologic information, as well as protecting U.S. government communications and information systems.

Other agencies have different core roles: the CIA concentrates on foreign human intelligence and covert operations rather than technical SIGINT; the FBI handles domestic security, counterintelligence, and cyber investigations; the Department of Homeland Security focuses on safeguarding the homeland and coordinating security efforts. These distinctions explain why foreign SIGINT is led by the NSA.