For over a quarter century, Iran has been one of America's chief nemeses. Ever since Ayatollah Khomeini overthrew the Shah in 1979, the relationship between the two nations has been antagonistic: revolutionary guards chanting against the Great Satan, Bush fulminating against the Axis of Evil, Iranian support for Hezbollah, and President Ahmadinejad blaming the U.S. for the world's ills. The unending war of words suggests an intractable divide...