Academic journal article Naval War College Review

THE OTHER ULTRA: Signal Intelligence and the Battle to Supply Rommel's Attack toward Suez

Academic journal article Naval War College Review

THE OTHER ULTRA: Signal Intelligence and the Battle to Supply Rommel's Attack toward Suez

Article excerpt

S ince the revelation of the Ultra secret in 1974, it has been widely accepted that Ultra intelligence-that is, high-grade Axis codes decrypted by a centralized British interservice unit called the Government Code and Cypher School (GC and CS) at Bletchley Park-gave Great Britain a decisive advantage over its Axis foes and that this advantage was particularly significant in the battle against shipping to North Africa. As early as 1977, Harold C. Deutsch, a historian and head of research for the OSS (or Office of Strategic Services, the World War II forerunner of the U.S. Central Intelligence Agency), concluded that the "systematic strangulation of [Rommel's] services of supply" due to knowledge of Axis schedules and convoy routes was a "decisive ingredient of British . . . victory in the Mediterranean." Deutsch's conclusions, reached thirty-six years ago, have been affirmed in official and popular histories and remain essentially unchallenged today.1

The geography of the North African campaign, which was fought from June 1940 to November 1942 between the forces of the British Empire and the Axis powers of Italy and Germany, dictated that nearly all materiel had to reach the front over water. In the case of the Italo-German army, shipments could only arrive at the widely separated ports of Tripoli, Benghazi, and Tobruk. These harbors had the capacity to handle just a few freighters at a time, which limited convoy sizes, and during the period of the greatest Axis advance, July-October 1942, they were far behind the front line. An additional difficulty the Axis powers faced was that a British base, Malta, lay astride the shipping lanes from Italy to Libya. Nonetheless, in June 1942 an Italo-German army advanced two hundred miles into Egypt and threatened the Suez Canal. The Axis planned to continue its advance to Cairo, Suez, and maybe beyond. But to do so it would need fuel, ammunition, men, vehicles, and other materiel, and this, except for some men and tiny quantities of fuel and munitions, could arrive only by sea.2

At this critical juncture the British made every effort to deny Field Marshal Erwin Rommel's Panzerarmee Afrika the materiel it required. According to the official history British Intelligence in the Second World War, written mainly by F. H. Hinsley, a Bletchley Park analyst, the ability of the British to intercept and decipher many Axis secret communications, especially those encrypted by the supposedly unbreakable Enigma device, gave them knowledge of the course and composition of every Axis convoy to Africa before it sailed. Ultra contributed to the defeat of the Axis thrust to Suez because it allowed the targeted sinking of tankers and denied Panzerarmee Afrika the fuel it needed just prior to its last attempt to reach the Nile River on 30 August 1942. Hinsley writes, "Of the 48 Axis ships sunk in the period from 2 June to 6 November . . . only one (766 tons) was not reported to the Middle East by GC and CS, while for all but two of the remaining 47 GC and CS provided either the location in port or anchorage, or the timing or routing of the final voyage, in good time for the operational authorities to reconnoiter and attack."3

However, historian Ralph Bennett-a Bletchley Park translator, and the author of a work about Ultra intelligence-writes, "But it is again permissible to wonder why [given such an advantage] the sinking rate was not higher."4 Indeed, few historians have asked how Italy, with some German assistance, managed as it did to deliver the great majority of supplies dispatched to Africa. Over the course of thirty-six months, 2.67 million tons of materiel, fuel, and munitions were shipped to Africa-nearly all in Italian vessels and under Italian escort-and 2.24 million tons arrived. Deliveries exceeded 90 percent for seventeen months, and only twice, in November 1941 and May 1943, did the percentage of deliveries dip below half. Even during the decisive months of July and August 1942, prior to Rommel's last offensive, with Ultra in full effect, with Malta basing offensive forces, critical supply ports within easy striking distance of Egyptian airfields, and submarines operating from Haifa, Malta, and Gibraltar, more than 85 percent of materiel dispatched from European ports reached Africa. …

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