In the history of political clichés, has there ever been one quite so misjudged as the line—some version of which is attributed either to Israel’s martyred Prime Minister Yitzhak Rabin or fabled Defense Minister Moshe Dayan—that “you make peace with your enemies, not with your friends”?

OK, “give peace a chance” and “nation building at home” are worse. But the Rabin-Dayan line is an expression of the higher mindlessness that passes for wisdom among people who think they are smart. After Monday’s make-nice session between President...