CAIRO -- A think tank affiliated with the Arab League, the 22-nation group that seeks to forge a unified voice among its members, ended a two-day conference on "Semitism" this week at which participants labeled Jews "enemies of all nations," challenged the Jewish claim to Israel and cast doubt on the U.S. account of who was responsible for the Sept. 11 attacks. The Arab League, an important regional player that this year promoted a pan-Arab initiative for peace that held out the promise of normal relations with Israel, said it did not directly organize the event. However, it participated with...