 While this was an embarrassment for the British, it was the end of the German surface threat in the Atlantic.The loss of "Bismarck", the destruction of the network of supply ships that supported surface raiders, the repeated damage to the three ships by air raids, the entry of the United States into the war, Arctic convoys, and the perceived invasion threat to Norway had persuaded Hitler and the naval staff to withdraw.War had come too early for the German naval expansion project Plan Z. Battleships powerful enough to destroy any convoy escort, with escorts able to annihilate the convoy, were never achieved.