The minister was told about the HMS Royal Oak which was torpedoed by a German U-boat with the loss of 833 lives at Scapa Flow, off the Orkney coast, on 14 October 1939.

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The stated reason was the pressure of the tense international situation - a German U-boat's torpedoing of the RMS Lusitania in May of that year cost 139 American lives - but many reporters suspected Wilson had simply got tired of them.

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In 1916 Chaim Weizmann, who later became Israel's first president, worked out how to use chestnuts to solve the lack of acetone, a component of the cordite needed by the British navy to repel German U-boat attacks in the first world war.

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Roth expands it into a rich Louisiana picaresque, ranging far and wide as Benjamin tastes romance in Russia with the wife of an English diplomat (a beguiling Tilda Swinton), comes off second-best in an encounter with a German U-boat, and pursues Daisy, the love of his life, first to New York and then to Paris.

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