One of Congress’ key roles is oversight: making sure that the laws it writes are faithfully executed and vetting the military and diplomatic activities of the executive. Congressional oversight is meant to keep mistakes from happening or from spiraling out of control; it helps draw out lessons from catastrophes in order to prevent them, or others like them, from recurring. Good oversight cuts waste, punishes fraud or scandal, and keeps policymakers on their toes. The task is not easy. Examining a department or agency, its personnel, and its implementation policies is time-consuming. Investigating possible scandals can easily lapse into a partisan exercise that ignores broad policy issues for the sake of cheap publicity.