As zero hour approached in the battle of Europe, both sides were agog last week over secret weapons:
¶ The Nazis had the heavily secret jet-propelled planes of Britain and the U.S. to worry about. But the Nazis uncovered rocket planes of their own during raids on northwest Germany.
¶ Adolph Hitler, in his New Year's message, attributed the failure of his U-boats to "one single technical invention" by the Allies. Neither Hitler nor the U.S. Navy was more explicit, but Hitler probably referred to new submarine-detecting devices.
¶ What the press now calls the...