Operation Torch could not have been carried out without the prowess of British and American intelligence. According to Larry Collins and other renowned authors, the journey of convoy SL-125 would have been revealed voluntarily to the enemy intelligence services. For the Allies were far ahead of the Nazis in this respect.
From June 1941 onwards, British military intelligence called the methods used for wartime signals intelligence, obtained by breaking the high-level encryption of enemy communications picked up by the GC&CS (the forerunner of the British government’s electronic intelligence service) at Bletchley Park, Ultra. Eventually ‘Ultra’ became the standard name among Western Allied forces for any such decoding. This name was chosen because the information obtained was considered more important than the highest level of security used up to that point (‘The Most Secret’) and was thus termed ‘Ultra’ secret.
Most of the German coded messages were encrypted with an Enigma machine (in addition to Lorenz, Hagelin1 or PURPLE machines, of German, Italian or Japanese origin). Used correctly, Enigma would have been almost indecodable but negligence and mistakes made by the German cryptographers allowed the British to decrypt it and thus to have knowledge of all the messages exchanged by the Axis forces from spring 1942. To do this, the British cryptographers had also benefited from the precious help of the Poles. On 26 July 1939, only 5 weeks before the declaration of war, the Polish military secret services had indeed provided their British and French counterparts with techniques that allowed them to foil part of the Enigma codes.
Former Bletchley Park mathematician Gordon Welchman later wrote: “Ultra would never have really worked if we had not learned from the Poles just in time the details of both the German army, the Enigma machine and the procedures involved. At the time and afterwards, many experts considered Ultra to have been very valuable to the Allies. Winston Churchill said to King George VI: “It was thanks to Ultra that we won the war”. F. W. Winterbotham quoted Dwight D. Eisenhower, the Commander-in-Chief of the Western Allied Forces, as describing Ultra at the end of the war as having been ‘decisive’ in the Allied victory. Harry Hinsley, the official British intelligence historian during the Second World War, made a similar point about Ultra, saying that it had shortened the war ‘by no less than two years and probably four’. Without Ultra, it is not known how the war would have ended.
