The Iranian regime has its visions of Iran, which it expresses in public art that hangs above Tehran's traffic-snarled streets: Ayatollah Ruhollah Khomeini, the thunderous-browed father of the 1979 Islamic Revolution, scowls down from a giant mural; young men who perished in the eight-year war with Iraq, barely bearded, gaze out from their martyrs' fields of painted red tulips; protesters throw rocks at an Israeli flag; a Statue of Liberty sports a skull for a head; more mullahs, more martyrs. We Americans have our visions of Iran, too: seething crowds besieging the U.S. embassy, fanatical women in chadors. For us, the images add up to a nation with which we have no official diplomatic relations, only bitter words.