Federal involvement in risk assessment and management of hazards and disasters is a relatively recent development, primarily driven by major incidents like environmental contamination and industrial accidents. Responsibilities were initially held by local and state governments, but since 9/11 there has been increased federal focus on countering terrorism. The US government holds primary authority for crisis management to prevent terrorism, while states and localities have primary authority over consequence management to respond to impacts, with federal assistance as needed according to the Stafford Act.