The U.S. patent system has generated growing debate over whether it helps foster innovation or stifles it through unnecessary protections, as this Backgrounder explains.

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

U.S. missile defense in the twenty-first century is focused on emerging threats from North Korea and Iran, but critics say these systems are too costly and largely unproven.