Fake Pipes and Mixed Signals: Military Intelligence in North Africa in WWII

The North African campaigns of the Second World War are remembered for their tank battles, vast deserts, and colorful commanders. One of the most critical factors in those campaigns was military intelligence.

Stalking Supplies

The intelligence war, in which the British faced the Germans and Italians, was all about supplies. By decoding Axis signals, the British menaced enemy shipping bringing their supplies to North Africa while keeping their own safe. It gave them an edge despite longer supply lines.

It was built upon several layers of intelligence. Signals intelligence played the largest part. Some of it came from decoding local radio chatter. The decryption of the high-level Enigma code, a closely guarded secret, also fed into the decisions of top commanders.

Radio Failings

The Germans were also listening in on British radio signals. It was the undoing of some of the earliest British offensives. Pushed by Churchill into attacking before they were ready, the British advanced against Rommel and the Germans. Listening in on the signals between British tanks, the Germans discovered their opponents had almost no grasp of communications security. They found out about British plans and used the information to gain victory.

Rommel Gets Tricky

When he went on the offensive, Rommel turned the issue of signals intelligence around. By putting out false radio signals, he deceived the British about the location of a convoy of tanks. It allowed him to gain the element of surprise.

It was a case in which the British could have known better but failed to connect the dots of different intelligence sources.

By Bundesarchiv – CC BY-SA 3.0 de
By Bundesarchiv – CC BY-SA 3.0 de

Black CodeJanuary 1942 saw one of the Axis powers greatest intelligence coups. The Italians stole a copy of the Black Code, used by the US Military Attaché in Cairo to communicate with Washington. For six months, the Germans and Italians listened in on everything the Attaché transmitted including a flood of British information as they kept their Allies up to speed on the African war.

It was not until July that the Allies realized what was happening and this source dried up.

Winning on Intelligence, Struggling on the Ground

Despite these setbacks, the Allies usually had the upper hand in the intelligence war. They had better cryptographers and the information gained from Enigma was used selectively, so they benefited from this source without giving away that they had it.

However, they struggled to turn it into victories on the ground. Rommel was a skilled commander, and it took time for the war to turn against him. As well, British leaders often lacked the experience and knowledge to use the intelligence they had effectively.


The Gazala offensive which began at the end of May 1942 showed that the British were starting to get a handle on their intelligence. Through intercepted signals and the interrogation of a prisoner, they learned the outline of Rommel’s planned offensive. Then an Enigma intercept gave them the code word for the launch of the attack – Venezia.

They knew the attack was coming 24 hours in advance. Rommel’s planned breakthrough came to a bloody and exhausted halt.


One of the best Allied assets was a double agent known as Cheese. An Italian Jew in Egypt, he became a British agent feeding the Italians false information. After being recalled by the Italians, he was replaced by a “friend” who was, in reality, a British signalman. His apparently useful messages to Italian intelligence were soon being passed straight to Rommel, letting the British feed him all manner of false information.

Taking Prisoners

Prisoners of war were a vital source of information. As the British went on the offensive in 1942, this source became indispensable. They swept up Germans and Italians left behind in retreats, gaining a greater understanding of Axis formations and plans.

Trickery at Alamein

One of the best acts of deception came at Alamein in October -November 1942. The Germans had already been tricked about fictional troops and misdirected about where British forces were, but this could have been undermined if aerial reconnaissance did not match the false intel.

The British built a water pipeline south. Its direction and the time taken to erect it indicated a significant attack was coming in November in the south.

Meanwhile, the real preparations were underway further north. When the attack came, it sent Rommel reeling.


The planning for Operation Torch, in which the Americans joined the war, showed the limits of Allied learning. Those commanders who had already fought in the desert war understood what intelligence could do in modern warfare. The new American and British officers coming in for the expanded operation did not. New intelligence officers, although well educated, lacked vital practical experience. Commanders did not know how to use intelligence.

The British Army in North Africa 1940
The British Army in North Africa 1940

The campaign could have gotten off to a better start, but it was still a success. The business of learning intelligence techniques began all over again.

Radio Silence

One of Rommel’s last intelligence coups came at the Battle of Kasserine Pass, his first substantial fight against the Americans. There, he avoided transmitting orders over the radio. The Allies were left in the dark.

The American troops were caught by surprise, bringing Rommel success on the ground. However, the Allies had the strategic advantage, and the end was in sight.

Patton and the End

General George S. Patton was one of the African arena’s last converts to the value of intelligence. After coming to grief in an ill-planned attack in March 1943, he realized how intercepted signals could help him. Unfortunately, he then talked about it on an open radio channel, leading the Germans to change their code.

Right to the end of the campaign, intelligence proved vital, telling the Allies where Hitler was sending his ill-fated reinforcements. Never before had the behind-the-scenes war of intelligence been so central to a military campaign. It was a sign of things to come.


Ralph Bennett (1999), Behind the Battle: Intelligence in the War with Germany 1939-1945.

Andrew Knighton

Andrew Knighton is one of the authors writing for WAR HISTORY ONLINE