Last month, in an essay in the New York Times, columnist Roger Cohen cited an American protagonist in a Philip Roth novel who said that "in England, when someone mentions the word 'Jew,' I notice that the voice always drops a little." Anti-Semitism is always just beneath the surface in England, Cohen observed. Conventional stereotypes can surface in genteel conversation.

Cohen then explored another minefield of identity: he related how in the U.S. he has been accused by other Jews of not being a real Jew or of being a "self-hating Jew," because he has criticized Israel for what he calls its "self-defeating expansion of settlements in the West Bank." His essay—and the critical response he received—is one sign of how difficult it is for Jews to talk about the Israeli-Palestinian conflict.

It is also difficult for Christians to talk about it with Jews. In August, Glenn Beck, the former Fox News talk-show host, toured Israel and held a "Restoring Courage" rally in Jerusalem. His aim was to display American solidarity with Israel. Beck's visit was embraced by some Israelis, who are eager for such expressions of support, and reviled by other Israelis, who noted Beck's penchant for anti-Semitic outbursts and extreme anti-Muslim rhetoric. "If this is the only kind of friend Israel's government can find around the world, that's a very poor sign," said Yariv Oppenheimer, secretary-general of Peace Now.