The West is more of a worry. Could the civilisation that gave the world the industrial revolution, modern medicine, the Enlightenment and rational inquiry, liberal democracy, just war theory, Beethoven, Brahms and the Beatles, really be contemplating terminal decline? By and large, the Jews are not seeking to enact their own demise. I generalise, and there are notable exceptions.The tradition of the blood libel, invented in 1144 by a Jewish convert to Christianity called Theobald of Cambridge, is echoed today by his ideological descendants, the likes of Zack Polanski, the Jewish leader of Britain’s Green Party, who has supported the...