From the Introduction: "Successive U.S. Administrations have identified Iran as a key national security challenge. The Trump Administration has articulated its assessment of the threat posed by Iran in testimony by U.S. officials, statements, and reports such as an annual Defense Department report on Iran's military power required by successive National Defense Authorization Acts (NDAAs) and a September 2018 State Department report entitled 'Outlaw Regime: A Chronicle of Iran's Destructive Activities.' This report analyzes Iran's foreign and defense policies and capabilities to implement its policies."
CRS Report for Congress, R44017
Congressional Research Service: https://crsreports.congress.gov/