How two Islamic sects traded places in the American mind.

This is not the first time the United States has become obsessed with an Islamic terrorist menace. For a decade after the Iranian revolution of 1979, Americans had nightmares about militant Muslims. But they were not the same militant Muslims that we fear today.

Ayatollah Khomeini had galvanized Shiite masses—Shiites are a minority sect of Islam who are dominant in Iran—for his revolution, and Shiites were soon implicated in appalling attacks on Americans. In 1979, Shiite militants took U.S. Embassy personnel hostage in Tehran. During the '80s, Hezbollah, the Iran-backed Shiite terrorist operation in Lebanon, took hostages, hijacked airplanes, and murdered hundreds of Americans in suicide bombings at the U.S. Embassy and Marine barracks in Beirut. Shiites, as one newspaper put it at the time, "are synonymous with terror in the American consciousness."

American intelligence experts warned that Shiite training camps in the Iranian mountains were preparing thousands of militants for a holy war against the United States. Charismatic, homicidal Shiite imams were providing theological armor for the young warriors, preaching on the corruption of the modern West and on the need to rebuild the Muslim empire. A "Shiite International" in Tehran was allegedly coordinating the anti-American jihad. Americans grew wary of Shiites in the United States: Young Iranian students were suspect.

The Shiite scare was founded partly on the belief that Shiites were inherently prone to anti-Western violence. American analysts examined Shiite religious practices and asserted that the heart of Shiah Islam was a "not rational," "violently reactionary" "extremism." Fascination with martyrdom supposedly defined Shiites. Their central holiday remembers the martyrdom of Hussein, one of Muhammad's descendents, and some Shiites commemorate by flagellating themselves with whips. A reporter dubbed this "a ceremony that spawns suicide bombers."

Still, Americans could console themselves that not all Islam posed such mortal danger. Shiite extremism was contrasted with dominant Sunni Islam, which was "rational" and "moderate" and valued power and stability. We could deal with Sunnis: Sunni Egypt and Saudi Arabia were considered buttresses against Shiite madness.

But now, in the American mind, Shiites have become Sunnis, and Sunnis have become Shiites. We say the same things about the zealous Sunni followers of Osama Bin Laden and the Taliban that used to be said about Shiite militants. According to intelligence experts, Bin Laden's training camps in the Afghan mountains have prepared thousands of militants for a holy war against the United States. Charismatic, homicidal Sunni clerics are providing theological armor for the young warriors, preaching on the corruption of the modern West and on the need to rebuild the Muslim empire. A single group, al-Qaida, is supposedly coordinating the global jihad. Americans have grown wary of Sunnis in the United States, especially young Saudi men.

As with the Shiite anxiety, there is a belief that this particular kind of fundamentalist Islam is inherently violent. The belligerent Wahhabism of Bin Laden and the Taliban is a "warrior religion," a "steel-tipped Islamic fundamentalism." It, too, celebrates the idea of martyrdom and views violence as "a means of purifying a corrupt world."

Our old Shiite enemies, on the other hand, are now seen as moderates. Iran despises the Taliban and Bin Laden: The Taliban has murdered Afghan Shiites and executed Iranian diplomats. So it's not surprising that Iranian elected leaders, notably President Mohammed Khatami, have made friendly overtures toward the United States since Sept. 11. American media coverage now emphasizes that Iran is much more democratic than its neighbors, that it has abandoned—or at least curtailed—its support for Islamic extremists, and that it is the most stable, rational state in the region.

(The Sunni-Shiite exchange has even infected Capitol Hill culture. A few years ago, liberals would call Christian conservatives "the Shiite wing of the Republican party." These days, lefties refer to Christian conservatives as "The American Taliban.")

Of course there are still extremist Shiites, and relatively moderate Sunnis still control the biggest Islamic states. But why have Sunnis and Shiites traded places in the American Zeitgeist? Shiites have shed their dreadful American reputation because Shiite extremists really have moderated. The Iranian revolution is 22 years old. Iran is no longer an infant state: It is an adult. It has lost a war with Iraq and lost its spiritual leader Khomeini. It no longer preaches global Islamic revolution. Iranians lived with militant religion for years, saw how oppressive it was, and have (partly) democratized and (slightly) loosened up as a consequence.