Ultra In World War II

Examine and Evaluate the role of ULTRA in the Second World War

The role of Ultra was for the best part unknown until the early 1970`s when F.W Winterbotham published his book "The Ultra Secret". Since then historians have differed in their view of whether or not Ultra was a decisive factor in the Second World War. Throughout this essay I shall be arguing the case that during the Second World War, Ultra decrypts possessed the continual potential to be the decisive factor in any theatre, but for the most part never fulfilled this potential due to both human and technical factors. Putting Ultra's role in perspective can only be achieved, not by examining the extent to which the Allies decrypted the Enigma ciphers, but of what use it was to them. In F.H Hinsley`s words its "the problem of distinguishing between having intelligence about the enemy and being able to use it."1. When this is done it becomes apparent that Ultra's role differed greatly between theatres and between the different aspects of warfare. For instance, it can be argued that Ultra played a much more significant role where supplies where concerned as opposed to land warfare; events moved too quickly in the latter for Ultra to be able to distribute its findings whilst their relevance remained. Although Ultra is a much celebrated topic in literature on the Second World War, it is fair to say that its role was severely limited for several reasons. In the field of supplies I feel that Ultra played its most important role, helping to obliterate the Italian Merchant fleet, and helping to turn the tide in t he Allies battle with the U-Boats in the Atlantic, which ultimately led to victory in the North African theatre and made the landings in Normandy possible.


From the interception of Ultra signals all the way to the information being put to use on the strategic or tactical maps there were numerous difficulties at every stage. In gathering and analysis as well as distribution and application, Ultra faced bureaucratic, technical, human and logistical limitations which resulted in Ultra's potential not being exploited to the full and its significance as a whole to the Second World War reduced considerably. Ultra was only one piece in a very big jigsaw and when i t was used effectively it could not turn a battle around single-handedly. From the history of the Second World War it can be seen that Ultra's role was not always significant, but it did possess the continual potential to be the decisive factor in a battle, as is proved by Allied successes such as Midway and the shooting down of Yammamoto`s plane in the pacific war. So if Ultra had the potential to be a decisive factor then why wasn't it so on most occasions ? "Not many of the decrypts directly illuminated the enemy's intentions and of these some necessarily reached the Western Desert too late to be of immediate use."2 Protection of the top secret Ultra source meant that the distribution of Ultra was extremely slow and by the time it had reached the relevant commander it was often out of date and therefore at best useless and at worst misleading. Another factor outside Ultra's control was the fact that it was almost all low grade SIGINT that was intercepted, which gave details of movements, equipment specifications and supplies on some occasions, but most of which contained trivial information. Again Ultra had the potential and did on rare occasions intercept high grade SIGINT, but Ultra never revealed the whole picture, warned of future attacks or unveiled the enemy's strategy. The enemy was not a static one with ciphers being changed, some never being broken again and others taking valuable time to re-break. These operational problems added to the limitations that Ultra faced all through the war. Technological factors also destined the distribution of Ultra to be extremely slow as communications technology was not developed enough to provide swift delivery over long distances with the required security. " Information about the enemy was frequently treated as interesting rather than valuable"3, so when the SIGINT was finally received by the relevant commander it was not always trusted. Commanders such as Montgomery disliked the rather ungentle manly form of warfare and therefore thought it not as important as maybe they should have. Ultra was hindered in its gathering and analysis and application, but still proved itself valuable on several occasions. In North Africa Ultra intercepts of supply movements fro m Sicily and southern Italy to North Africa resulted in decisive strikes on Italian convoys by Force K in Malta, Force H in Gibraltar and Force B in Alexandria, which in 1942 forced Rommel to strategically switch to the offensive when tactically he wouldn't have done otherwise. Ultra gave early warning of the Germans plan to enter the Balkans and help Italy in its conquest of Greece, and the early breaking of the Luftwaffe enigma cipher enabled Britain to fight the Battle of Britain very effectively and to receive early warning of any coming offensive, as the Luftwaffe were always involved.


Therefore from analysis it can be seen that Ultra did not in itself enable the Allies to win the Second World War, but was simply another important factor to the allies advantage. Neither do I feel that Ultra accelerated the defeat of the Axis powers which is a widely held view among scholars. The only real basis for a claim of this type is the fact that the Allies, through Ultra sources, knew that Japan was preparing for an attritional battle to defend the Japanese Islands themselves and that this led to the decision to use the Atomic bomb. However this is very misleading as the Atom bomb would have been used regardless of Ultra decrypts simply because it was seen as a military weapon and a means to an end. Throughout the war Ultra performed a sieve like operation, where thousands of decrypts were analysed and only a very few were found to be worthy of passing up to a higher authority and of those, even fewer would be acted upon. "Information was confused by the enemy's own uncertainty"4 and indeed pre ceding the battle of Gazala in North Africa in 1942 the Allies were misled entirely into thinking Rommel had lost the best part of his armour and was planning to deploy defensively, when in actual fact he was being indecisive and eventually decided on offensive action with superior armoured forces. Ultra's role in the Second World War was supplementary, to add to the information known by Allied commanders, and any exaggeration of this role is misleading. Ultra alone did not change a commander's mind and indeed it s consultation was preceded by other far more immediate and significant concerns, such as one's own capability. The situation in Crete illustrates the fact that "Intelligence however brilliant, cannot provide dramatic success where military strength or preparedness does not exist"5, that although Ultra could give vital information to the Allies, it could not win the battle itself. Allied capability in the Mediterranean was the primary factor that led to the fall of Crete and there was nothing that Ultra could do about this. Knowledge of the enemy's weaknesses is of no practical value unless you have the capability to exploit it. The Allied knowledge gleaned from Ultra that the Germans were about to attack Greece did allow the them to send forces, but the Allied capability was such that it was not possible to have a realistic chance of winning the conflict there. Again in May 1942 although the Eighth Army had "good general warning of the imminence of Rommels attack, the British lost the battle of Gazala"6.


Ultra was an added bonus to the Allies, not their primary source of wisdom. It was consulted by commanders in planning stages or when an important decision was to be made. I also feel it is worth mentioning that Ultra achieved what I term hidden successes in the Second World War, in as much as the consequences of its input were more long term than immediate. For instance it is true to say that although Ultra failed to stop the successful invasion of Crete, the resistance the Allied forces were able to give (as the precise plans of the invasion were known) helped to persuade the Axis powers to firstly postpone and then to cancel a similar invasion of Malta. Again with Greece the consequences were felt much later by the Germans as the delay that Allied resistance caused in Greece meant that Operation Barbarossa was postponed and valuable time was gained by , which was rearming as fast as it could. The battle of the Atlantic was perhaps where Ultra had it finest hour. In May 1943 the Germans lost a stagger ing 31 U-Boats due to the fact that the Allies had finally cracked the Triton Enigma cipher that the U-Boats used. In the Mediterranean, the Atlantic and the Pacific Ultra proved a decisive factor in helping the Allies to eliminate the threat of losing the war to the U-Boats and therefore being able to supply Britain, Russia and North Africa. Ultra also had a negative role in the Second World War, by which the Allies could gauge if their deception techniques were successful and whether the Axis forces had knowledge of Allied operations or not. This 'no news is good news' role which Ultra performed especially well preceding the Allied Torch landings in North Africa was extremely useful to the Allies in planning operations for Torch and in the future ones too. The effectiveness with which Ultra was processed was significantly improved towards the end of the war which led to its role being enhanced to some extent.


Ultra was only one intelligence source among many. Other sources ranged from reconnaissance, both ground and air, POW interrogation, other SIGINT and reports from contacts on the front line and the relevant commanders history in battle. From analysing their impact upon operations it is possible to assert that they were themselves more significant a factor than was Ultra although again Ultra always had the potential to be decisive. Ultra was never used as an infallible source, but instead it was corroborated with these other sources to gauge its reliability. Since the release of many of the Ultra documents Ultra's role in the Second world War has been greatly exaggerated, being elevated to the rank of a decisive factor. Such an assertion involves the overlooking of the numerous and crippling limitations of t his form of intelligence, technically and operationally. Through analysis of such limitations, in relation to its isolated successes, it can be seen that Ultra was no more than a supplementary factor in the allies favour, complimenting their knowledge of the Axis powers and their forces, as it sat in the background sifting through decrypts until it found information worth passing on to a higher authority. Eventually during this sifting process Ultra enabled the Allies to know immensely useful information about its enemy and, although rarely in the short term, due to the slow speed of its distribution , Ultra did achieve decisive victories for the Allies in the long-term over its Axis counter-parts. Towards the end of the war Ultra was becoming established as a significant weapon in the Allied armoury, being more effectively used, whilst still remaining undetected. It was the selective use of Ultra decrypts that sustained its role throughout the Second World War, avoiding attention, rather than risking th e loss of this 'most secret source' through over-intensive use on its discovery. Ultra alone put intelligence on the map and "brought a new dimension into the prosecution of ...war"7, and as such, it indeed had the potential to be a decisive factor, and its use certainly was to the Allied advantage, but its role should not be exaggerated further, as the usefulness of its decrypts were vastly restricted by its inbuilt limitations as a system of intelligence, and as a result it cannot be said to have won or even shortened the Second World War for the Allies.

Bibliography McNeill, W.H Survey Of International Affairs - 1939-1946 : America, Britain and Russia, their Co-operation and Conflict. (Oxford University Press 1953) Winterbotham, F.W The Ultra Secret (Wiedenfeld and Nicolson 1974 ) Hinsley, F.H British Intelligence in The Second World War - Its Influence on Strategy And Operations Volume One. (Her Majesty`s Stationary Office, London 1979 ) Hinsley, F.H British Intelligence in The Second World War - Its Influence on Strategy And Operations Volume Two. (Her Majesty`s Stationary Office, London 1981 ) Keegan, John The Times Atlas Of The Second World War. (1989) Young, Peter Purnells Encyclopedias of the Second World War. (1972) 1 British Intelligence In The Second World War - Volume Two p367 2 British Intelligence In The Second World War - Volume Two p376 3 British Intelligence In The Second World War - Volume One p 215 4British Intelligence In The Second World War - Volume Two p312 5 The Ultra Secret p187 6 British Intelligence In The Second World War - Volume Two p366 7 The Ultra Secret p187


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