Four decades of conflict with Iran, explained

Iran and the U.S. have been enemies since 1979. Why? Here's everything you need to know:What is the state of relations? For four decades, the U.S. and Iran have been locked into what is essentially an ongoing, low-grade war. Since its inception in 1979, the Shiite theocracy, now run by Supreme Leader Ayatollah Ali Khamenei and a council of top clerics, has considered the U.S. the "Great Satan" — an intruder in the Middle East and a primary obstacle to the mullahs' goal of sustaining and sp