Few European Jews speak or understand much Arabic. But there is one phrase many have recently come to know: "Khaybar Khaybar ya-Yahud, jaish Mohammad saya'ud." The words refer to the battle of Khaybar, in which the Prophet Mohammed slaughtered and enslaved hundreds of Jews, including women and children; "Mohammed," it means, "is coming back for you." It is a death threat to Jews everywhere, and it is being shouted out with growing frequency these days on the streets of Paris, London, Amsterdam, and Berlin.
What's worse, increasingly the threat is not merely idle: in one of the worst episodes of anti-Semitic violence to hit Europe since the Holocaust, Jews are being attacked in their synagogues, their shops, and even in their homes.
And most experts believe things are going to get worse.