The history of the Iran-United States relationship is complex and often brutal. Understanding it helps put today's turmoil into sharper focus.
Donald Trump stepped back from launching US airstrikes inside Iran, but the conflict is unabated and there appears to be no way out of confrontation for now.
The US has imposed new sanctions against Iran's top leaders, but its foreign policy has no clear focus.
A terrorism expert exposes the quirks, inconsistencies and foreign policy strategy behind the State Department's terrorist watchlist.