FILE - In this Feb. 2, 1979 file photo, Ayatollah Ruhollah Khomeini, center, is greeted by supporters in Tehran, Iran. Friday, Feb. 1, 2019 marks the 40th anniversary of Iran‚Äôs exiled Ayatollah Ruhollah Khomeini return to Tehran, a moment that changed the country‚Äôs history for decades to come. That revolution would spark the U.S. Embassy takeover and hostage crisis, stoking the animosity that exists between Tehran and Washington to this day. (AP Photo, File)