Hitler's original orders to wage war only in accordance with the Prize Regulations, were not issued in any altruistic spirit but in the belief hostilities with the Western Allies would be brief. On 23 September 1939, Hitler, on the recommendation of Admiral Raeder, approved that all merchant ships making use of their wireless on being stopped by U-boats should be sunk or captured. This German order marked a considerable step towards unrestricted warfare. Four days later enforcement of Prize Regulations in the North Sea was withdrawn; and on 2 October complete freedom was given to attack darkened ships encountered off the British and French coasts. Two days later the Prize Regulations were cancelled in waters extending as far as 15° West, and on 17 October the German Naval Staff gave U-boats permission to attack without warning all ships identified as hostile. The zone where darkened ships could be attacked with complete freedom was extended to 20° West on 19 October. Practically the only restrictions now placed on U-boats concerned attacks on passenger liners and, on 17 November, they too were allowed to be attacked without warning if clearly identifiable as hostile.