The jihadist murderers are dead, after killing five more Parisians, but many Westerners, long drugged by bad ideas and received wisdom, continue to sleepwalk through the war against jihadism. This means that after all the brave words and feel-good marches, little significant action will be taken to prevent such atrocities from happening again. In the absence of clear thinking and recognition of fact, responses to this latest example of Muslim violence reflect ideological fever dreams. “Nothing to do with the Muslim religion,” as French president François Holland said of the attacks, is a perennial favorite. Such apologists invoke shopworn Marxist...