"I invite you to embrace Islam,” says Osama bin Laden in his latest videotape. Most analysts take this as pious window-dressing and focus on what they believe to be the more substantive points of his message: his comments on the war in Iraq, his critique of capitalism, the similarity of much of what he says to Democratic Party talking points, and the like. But in fact the invitation to Islam is the heart, and the most revealing aspect, of bin Laden’s entire statement. The chief reason for this, of course, is because in traditional Islamic law, the invitation to Islam...