When Pope John Paul II went to the Middle East in 2000, a trip that was called "historic," he left a note at the Western Wall apologizing for Christian anti-Semitism. This week's visit by Benedict XVI takes place under different circumstances. Peace between Israel and the Palestinians seems more elusive than ever, and Benedict himself has contributed to ill-feelings. He lifted the excommunication of a bishop who's denied the Holocaust and linked the Prophet Mohammed to violence. Though Benedict describes himself as a "pilgrim of peace," "the world may be excused for holding its breath," according to John Allen, senior correspondent for the National Catholic Reporter.