The division protects the United States against foreign intelligence operations and espionage.

It accomplishes its mission of hunting spies and preventing espionage through the use of investigation and interaction with local law enforcement and other members of the United States Intelligence Community.

In the wake of the September 11, 2001 attacks, the division's funding and manpower have significantly increased.

[9] Some sections include: The division was first established by FBI Director J. Edgar Hoover in 1939 as the General Intelligence Division, to handle foreign counterintelligence and other intelligence related investigations.

In 1999, the FBI's Counterterrorism Division was created and took over responsibility for terrorism related investigations.