Here, in mobile desert warfare, radio was the only possible form of communication—a medium as dangerous as it was valuable—and the British used it more carelessly than ever.

– Lieutenant General Albert Praun

In the spring of 1941, Adolf Hitler announced from the Obersalzberg Berghof, his Bavarian alpine retreat, that the Germans would establish a “blocking force” in Libya “for reasons of strategy, politics, and psychology.” The rising star of the Wehrmacht, Lieutenant General Johannes Erwin Eugen Rommel, was hand-selected by Hitler to command a light, mobile, mechanized force, initially consisting of two divisions: the Afrika Korps. What then transpired over the next two years on a “camel-thorn-studded plain” is a clear testament to the power of leadership, improvisation, energy, and tactical genius of one man versus a determined enemy and the calumnies of a distant, moribund higher headquarters. To any military historian, or budding maneuver commander, it is a master class in motorized, combined arms, maneuver warfare—a numerically inferior, poorly supplied, and strategically irrelevant force embarrassed the British Goliath not once, but twice. It did so by embodying Napoleon’s ethos—”activité, activité, vitesse”—or more plainly, by fixing the enemy’s main force with a demonstration, while the decisive force plunges into the enemy’s rear area or an exposed flank. And did I say improvisation?

But Rommel’s capacity for combined arms warfare has been discussed ad nauseum. It is generally held that Rommel was simply the rare combination of a military genius and a gambler. A man with the coup d’oeil and a penchant to use it. Rommel would chafe at this notion his entire life, not too dissimilar to retired General James N. Mattis’s disliked of his moniker “Mad Dog.” However, to any outside observer, the facts are startling to consider. In the pursuit of chasing the British out of Africa, Rommel reduced his army to a mere reinforced battalion and often resupplied his formation wholesale with petrol and ammunition from captured stores. In his final thrust, most of his nonarmored carriage was of British origin. Can anyone even imagine a US Army equivalent? The only thing that comes to mind is Geronimo—1st Battalion, 509th Infantry Regiment. However, that comparison is not entirely fair (to Rommel), since in its role as the opposing force unit at the Joint Readiness Training Center Geronimo is made up of US soldiers pretend-fighting other US soldiers over the same ground eleven times a year, and with home-field advantage. It is a generally understood that Geronimo knows exactly what its adversary will do. There are only so many things you can do in the box—the training environment where they fight. So, to an outsider observer, knowing nothing, Geronimo behaves in a way that appears freakishly high-risk, while its soldiers are in fact behaving rather logically and accepting only prudent risks. Without the benefit of repeated iterations of the same scenario on the same terrain, Rommel acted with similar audacity, seemingly knowing his enemy extraordinarily well. How?

There are two other items, rarely referenced, that may explain how he was able to thrust so apparently recklessly into the British forces’ flanks and nearly drive them off the continent—how one man, for a time, threatened the Allies’ possibility of victory. These other items, conveniently, for this essay at least, are two things that the US Army is currently struggling mightily with as it continues its pivot toward preparing for large-scale combat operations. While Rommel would have referred to one of the two as the Nachrichten Fern Aufklärung Kompanie621 (Signals Intercept Company 621) and the other as die gute Quelle (“the good source”), we would call the two items tactical and strategic signals intelligence.

Rommel and the Intercept Company

After being recalled from North Africa, Rommel was anxious about his legacy. As his son, Manfred, recounts in the introductory pages of The Rommel Papers, Rommel became increasingly motivated to leave an “objective account” to rebuff the many criticisms, misinterpretations, and jealousies that would invariably malign his record. The autobiographical record that was eventually published by B. H. Liddell Hart (a British contemporary) captures Rommel’s battlefield sketches, letters to his wife and son, tactical and strategic ruminations, and postcampaign reflections. In other words, it provides an unparalleled window into Rommel’s success and failure in North Africa. For the sake of this essay, though, it is almost a dubious source (almost), as it nearly fails to mention his intelligence service, let alone a niche, inchoate field of that service called wireless intercept. We can be moderately comforted with the fact that Rommel rarely mentioned staff officers, or even commanders, by name. Nor did he often single out specific acts of bravery or memorialize herculean efforts on his staff. More often he would praise them broadly: his Africans!

In fact, Rommel only mentions wireless intercept twice in his memoirs. In June 1941, Rommel discusses how a series of wireless intercepts cemented his opinion that the British had been defeated during the Battle of Sollum.

In wireless messages which we intercepted they described their position as very serious. The commander of 7th Armoured Division sent a request to the Commander-in-Chief of the desert force to come to his headquarters. It sounded suspiciously as though the British commander no longer felt himself capable of handling the situation. . . . The enemy wireless was repeatedly reporting lack of ammunition. . . . They complained bitterly of their high casualties.

And again, much later, Rommel describes an intercept shortly before the Battle of El Alamein and the destruction of Signals Intercept Company 621.

Towards midday we learned from radio interception that the British were leaving Haneish. I immediately gave orders for the retreating Tommies to be picked up, and a considerable number of prisoners was brought in as a result.

Here we have the only direct evidence from Rommel that wireless intercept influenced his decision-making and the posture of his forces. Although other people in Rommel’s command would attribute much of his success to it—in fact an entire book was written on it—it is somewhat peculiar that he never seriously enumerates how various sources of intelligence informed his view of the fight. However, even if Rommel happened to omit a final scoring of what intelligence collection method (e.g., aerial or vehicle reconnaissance, prisoner interrogation, etc.) was the most impactful in the North Africa campaign, his actions and philosophy betray an absolute reliance on signals intelligence.

In The Rommel Papers, the reader can observe, in several places, Rommel taking great pains to make plain his tactical and strategic thinking, and how he was remarkably clear-eyed in his appreciation of the social, cultural, and physical realities of the war in North Africa. Rommel was undoubtedly intellectually gifted, a vivid writer, and capable of matching many luminaries of his time, but he appears to distance himself from the then fashionable “academic” soldier.

There often occurred to me the difference between the Professor of Economics and the business man, as judged by their financial success. The business man may not perhaps be on the same intellectual plane as the professor, but he bases his ideas on real facts and puts the whole power of his will behind their realisation. The professor, on the other hand, often has a false conception of reality and although perhaps having more ideas, is neither able nor anxious to carry them out; the fact that he has them is satisfaction enough. . . . The same difference can often be found between the academic and fighting soldier (emphasis added).

By any standard, contemporary or modern, Rommel would likely be considered a norm-challenging leader. He routinely worked his men to illness—himself included—was quick to fire commanders for failing to match his energy, and would disobey his superiors (even Hitler), when he thought the situation required it. For example, he would succinctly justify his initial thrust into Cyrenaica, a move that put him at odds with orders from the führer, created insane logistics problems, and subverted the heretofore agreed upon power structure with the Italians: “One cannot permit unique opportunities to slip by for the sake of trifles.” At the time, this decision made him somewhat of a marvel to his contemporaries and an enigma to his enemies. However, if your aerial reconnaissance, wisdom from years of combat, and common sense (i.e., the British supply lines snaked one thousand miles across the North African desert from Egypt) were all confirmed by timely wireless intercepts of British forces remarking on their sad state in the blistering sun, how might you respond?

Furthermore, Rommel lays out seven principles that he deems necessary for success in motorized warfare. Three of them are pertinent to this discussion because of what they reasonably demand of intelligence. The first is speed of reconnaissance:

Reconnaissance reports must reach the commander in the shortest possible time; he must take his decisions immediately and put them into effect as fast as he can. Speed of reaction decides the battle.

There was no reconnaissance method available to mankind in Rommel’s time faster than signals intelligence (nor is there now). Everything travels at the speed of light. Yes, some nontrivial time for filtering out intelligence of value is necessary, and then further dissemination can add to the delay, but by comparison to other methods of intelligence collection, like ground and aerial reconnaissance or human intelligence, it is magnitudes faster.

Second among the three of Rommel’s intelligence-centric principles is deception:

Deception measures of all kinds should be encouraged, if only to make the enemy commander uncertain and cause him to hesitate and hold back.

Every signal has the potential liability of being intercepted. However, if that is the intent than no deception activities can match signals intelligence scalability.

Finally, Rommel discusses exploitation of success:

Once the enemy has been thoroughly beaten up, success can be exploited by attempting to overrun and destroy major parts of his disorganised formations. Here again, speed is everything. The enemy must never be allowed time to reorganise.

Like reconnaissance, if speed is everything in exploiting success, then there is only one intelligence discipline that can keep up. It is hard to imagine that all these positive attributes of signals intelligence were lost on the general. And finally, although Rommel preferred the practical, sensible soldier to the acerbic academic, this should not be interpreted as meaning nontechnical. In fact, his philosophy held that military victories hinged on the rapid adoption of new technologies, both social and industrial.

The modern army commander must free himself from routine methods and show a comprehensive grasp of technical matters, for he must be in a position continually to adapt his ideas of warfare to the facts and possibilities of the moment. If circumstances require it, he must be able to turn the whole structure of his thinking inside out.

The most advanced, untested technology available to Rommel in 1941 was Signals Intercept Company 621. It was a lightly armed wireless interception unit outfitted with the most sophisticated radio and decryption equipment available. It was staffed by high-caliber, English-speaking cryptanalysts—“the sort who were waiters at the Dorchester” before the war. Its commander, Captain Alfred Seebohm, was a first-rate, ambitious officer who had studied electrical engineering in college before volunteering for the war and advanced rapidly once in. Rommel thought so highly of the company, especially after Seebohm predicted an imminent British offensive (Operation Battleaxe), he permanently assigned Seebohm’s executive officer and his team of cipher specialists to his own convoy, along with two radiomen explicitly for communicating with the intercept company. It was as unheard of in Rommel’s time for any company commander to have a direct line to the corps commander and staff as it is today.

Finally, we turn to an anecdote provided in The Rommel Papers by Lieutenant General Fritz Bayerlein, who gives his account of the 1941–42 North Africa Winter Campaign, since no copy of Rommel’s account survives. Bayerlein recalls a radio summons in late November 1941 for the commander of the Afrika Korps, Lieutenant General Ludwig Crüwell, to Rommel’s headquarters (after the Afrika Korps’s success in the spring and summer of 1941, it was reinforced and Rommel promoted to take charge of a new, higher command). After a long search in the darkness Bayerlein came upon a British lorry and two wireless trucks. Bayerlein crept up to the vehicles cautiously, unsure if they were friend or foe, and found Rommel with his chief of staff, unshaven and dusty but otherwise in great spirits because he had just finalized plans to surround the New Zealand Division the next day. What is telling about this anecdote is not just what is there but, more importantly, what was absent. To put this in perspective, Rommel was ten days into what became a rollicking, month-long battle for survival with the British on the Egyptian frontier, and all he required to plan a bold counterstroke was his chief of staff and two wireless trucks.

Signals Intelligence in Action

Rommel might have eventually gotten around to discussing the significance of wireless intercept on the North African plain. However, he would find himself implicated in a plot to assassinate Hitler. In a deal to save face for the Nazis and keep Rommel’s family and former staff safe, he ingested a cyanide capsule. Fortunately, one of Rommel’s former intelligence officers in North Africa, Captain Hans-Otto Behrendt, published an account of the two-year struggle from an intelligence perspective. It includes three critical examples that further underscore the significance of signals intelligence.

The first is the truth-is-stranger-than-fiction tale of Colonel Bonner Frank Fellers, which highlights what we today would call strategic signals intelligence or consider a national asset. In the fall of 1940, Washington sent US Army Colonel Fellers to its embassy in Egypt. Acting as a military attaché, Fellers wrote daily reports (which were intercepted by the Germans) on the “international political intentions or the fighting strength, equipment, reinforcements, campaign plans or morale of . . . allies in North Africa.” These reports included accurate, detailed insights and even top secret intelligence. It just so happened that the Italians had compromised the code that Fellers used for encipherment. While there are many versions of the story of how this occurred, supposedly Italy’s military intelligence service, in August 1941, bribed a clerk at the American embassy in Rome to allow the entire American military attaché code to be photocopied. This minor triumph in espionage gave the Germans what they called “the good source” and enabled all wireless transmissions from Fellers to Washington to be picked up by wireless stations in Germany, deciphered, translated, then sent directly to Rommel. This gave Rommel a clear view of British strategic plans, logistics, and overall strength. These strategic-level insights gave Rommel not only a quantitative picture of the British forces, but also somewhat of a qualitative glimpse at the command climate; many of his gambles could be attributed to his uncanny understanding of the forces involved in a local conflict and his instinctive knowledge of the opposing commander.

The second major example is all tactical. In Behrendt’s account, the wireless service early on was a bit player, providing largely reinforcing intelligence, until finding its footing in the spring offensive of 1941. On May 15, 1941, the British transmitted a sole wireless signal for an entire day: the German name “Fritz.” Signals Intercept Company 621, unable to make sense of this, declined to report it. The following morning, the British launched a surprise offensive against Halfaya Pass and the Sollum Front. After brief success, the Eighth Army was driven back. The offensive, known as Operation Brevity, had limited allied objectives, most of which failed, its chief success was the unintended instruction of British wireless predilections for the German intercept company.

From now on important new information was systematically acquired; it was of limited value on its own, but it could be supplemented, confirmed, or in some cases refuted by material from other sources, as occasionally happened when the enemy attempted diversionary maneuvers. . . . It was with the full company’s arrival that radio monitoring became our best source of intelligence.

On June 14, 1941, the British again transmitted a sole wireless signal: “Peter.” It was immediately reported. Signals Intercept Company 621 had already published intelligence on changes in British wireless frequency, order, and location, suggesting a complete tactical reorganization and an impending operation. The hastily planned counteroffensive, Operation Battleaxe, likely instigated by Winston Churchill’s irritation with the then Eighth Army commander, General Archibald Wavell, launched itself piecemeal into the teeth of Afrika Korps defenses. German intercepts had given Rommel just enough time to reposition his 88-millimeter antitank guns at Halfaya Pass, where they devastated the British Mark II “Matilda” tanks. Worse yet, Lieutenant General Noel Beresford-Peirse, the British officer in charge of the operation, opted to locate his command post sixty miles to the east at a Royal Air Force headquarters so he could better liaise. Much of Beresford-Peirse’s wireless traffic was intercepted. Rommel learned that the British main objective was “not a western envelopment by 4th Armoured Brigade” but an attack on Fort Capuzzo. That attack crashed into a spirited antitank defense instead of thinly held battlements. In a stroke of luck, a British codebook would find its way to Signals Intercept Company 621. The codebook mapped all the British cover terms for commanders, tanks, guns, and equipment, enabling the Germans to understand “the exact distribution of attacking troops.” The Eighth Army, in danger of annihilation, broke contact and retreated into Egypt. Although British casualties were relatively light, equipment losses were staggering—100 of 180 tanks lost to Rommel’s twelve.

The final, and most compelling, example of signals intelligence’s value to Rommel was the Battle of Gazala the following spring. In May 1942, the Eighth Army was defending a fifty-mile stretch of desert between Tobruk and Bir Hacheim, called the Gazala Line. The British enjoyed a 3:2 advantage in unit strength, 45:28 in tanks, and 8:5 in artillery, as well as about parity in the air. Not to mention the units were behind roughly half a million mines and other defensive obstacles. The only advantage Rommel had on paper was his antitank weapons. Rommel’s overall operational plan was a desperate gamble, betting on a two-pronged diversionary attack: the Italians would attack in the north with a simultaneous armored punch into the center by the German 90th Light Division, while the bulk of his force went on a long outflanking movement south to Bir Hacheim. Rommel, intent on selling his diversions, ordered a small cadre of trucks and tanks to be driven in circles day and night behind the Italians to give the appearance of large-scale tank assembly areas. Additionally, he had the armored forces feigning attack preparations on the center position followed by “lorries carrying aero engines and propellers” to stir up great clouds of dust. Rommel was counting on the British to split their forces. He anticipated that some British armor would be assigned to mind the feints in the north, while another, hastily assembled force would be sliced off to meet his decisive force rampaging in their rear. To summarize, a numerically inferior force further divides against an enemy in a defensive position, while pinning its success on the credibility of two diversions and the commander’s assumptions on British attitudes of risk. And yet, Rommel did not consider himself a gambler.

I hoped that the presence of the Italian Infantry in front of the 1st South African and 50th British Divisions would continue to persuade the overcautious British command to leave those formations complete in the Gazala Line.

This final curious comment by Rommel about his expectations prior to battle suggests he had not only significant insights into the current disposition of his enemy’s forces but also some small window into its command climate—and there is only one intelligence source that can provide such a thing in a timely manner. In case you were wondering, it worked. It is also generally considered to be Rommel’s most stunning victory.

Lessons for Today’s US Army

In the two-year struggle for supremacy in North Africa, the Eighth Army was almost always superior to German forces. In the final year the British enjoyed advantages in nearly all respects: tanks by 75 percent; armored cars, 750 percent; light guns, 180 percent; fighter planes, 300 percent; and bombers and reconnaissance planes, 50 percent. The British supply lines were also never truly in danger. Moreover, the British had tasted Rommel’s tactics. Yet at nearly every engagement, Rommel was able to apply his will to the battlefield. It was not until a triumvirate of calamities converged that Rommel’s weakness began to tell: the loss of “the good source,” the loss of Signals Intercept Company 621, and devastating supply-line interdiction by the British Navy and Air Force. I do not think it unreasonable to suggest that Rommel’s uncanny premonitions were the direct result of his understanding and utilization of tactical and strategic signals intelligence, which was at least far better than that of the British. Furthermore, the innate qualities of signals intelligence—complex, powerful, timely, and even unorthodox—fit Rommel’s personality and command climate, enabling him to improvise in ways the stodgy British simply refused to do. As his environment changed, the signals analysts could suss out new British organizations and locations—and often British plans and intentions—as dynamically as was required. Unlike every other intelligence source, this could be done nearly in real time.

But this essay is not meant to be merely a string of charming anecdotes about Rommel or his Signals Intercept Company 621. The intent of the essay is to drive home the anecdotes’ very real lessons. In a contest with a near-peer adversary, divisions and brigades cannot expect national-level organizations and assets to avail themselves at whim. National assets will quickly become saturated, stove-piped, and out of touch with maneuver commanders on the front lines. If we, the US Army, seek to be a credible deterrent, we must relearn and master the hard science of strategic and tactical signals intelligence—not just institutionally, but as individual commands and units. We must foster cooperation with organizations (like the National Security Agency) where this expertise exists. Most importantly, we must demand signals intelligence equipment, training, personnel, and responsiveness from the bureaucracy that a large-scale war against a near-peer enemy will require.

Major Matthew V. Powell is an FA49 (operations research and systems analysis) officer. He served previously as a battalion intelligence officer and as the commander of a signals intelligence company in the 116th Military Intelligence Brigade. He was selected for the junior officer cryptologic career program, which he participated in from 2021 to 2024.

The views expressed are those of the author and do not reflect the official position of the United States Military Academy, Department of the Army, or Department of Defense.

Image credit: Bundesarchiv, Bild 101I-443-1589-09 / Zwilling, Ernst A. / CC-BY-SA 3.0