To mark its fifth anniversary, Stephen E. Flynn, CFR’s leading national security expert, evaluates the general performance of the Office of Homeland Security.

Technology plays an increasing role in Homeland Security efforts, spawning a growing U.S.industry for everything from biometrics to cargo screening at ports.

The air travel system remains one of the most high-profile targets for terrorists. This backgrounder examines efforts to improve aviation security since the 9/11 attacks.