Mr. Ajami is a senior fellow at Stanford University's Hoover Institution and co-chair of the Working Group on Islamism and the International Order.

The Arabic word shamata has its own power. The closest approximation to it is the German schadenfreude—glee at another's misfortune. And when the Twin Towers fell 10 years ago this week, there was plenty of glee in Arab lands—a sense of wonder, bordering on pride, that a band of young Arabs had brought soot and ruin onto American soil.

The symbols of this mighty American republic—the commercial empire in New York, the military power embodied by the Pentagon—had been hit. Sweets were handed out in East Jerusalem, there were no tears shed in Cairo for the Americans, more than three decades of U.S. aid notwithstanding. Everywhere in that Arab world—among the Western-educated elite as among the Islamists—there was unmistakable satisfaction that the Americans had gotten their comeuppance.

here were sympathetic vigils in Iran—America's most determined enemy in the region—and anti-American belligerence in the Arab countries most closely allied with the United States. This occasioned the observation of the noted historian Bernard Lewis that there were pro-American regimes with anti-American populations, and anti-American regimes with pro-American populations...