The claustrophobic world of German U-boats was vividly evoked in the 1981 film Das Boot: the narrow steel tube in which the action is confined; the rivets popping out like bullets as the pressure squeezing the sinking submarine becomes intolerable; the sinister throbbing overhead as patrolling destroyers seek to explode their U-boat targets with depth charges; the frantic, sweaty tension between the crewmen as they jostle for space and survival. In Roger Moorhouse’s latest study of the Third Reich, he conveys all this and more.

Moorhouse has deservedly won a growing reputation among historians of Nazi Germany for combining academic rigour with readable narratives. Here he departs from his more usual political studies and attempts a close technical examination of Germany’s undersea war and the reasons for its failure.

The haunting fear that the U-boat wolfpacks – groups of submarines mounting concentrated attacks on Allied vessels – would sink enough supplies to starve Britain into submission was, Churchill claimed, the only worry that kept him awake at night. So insidious was the Allies’ concern – born in the First