The British Desert Army continued to dwindle throughout winter, as its supplies were increasingly chocked off and Rommel’s combined attacks steadily undermined its ability to resist. No sooner had the 56th Division entered the battlefield against Italian forces on 29 April then the British were forced to withdraw after suffering too many heavy casualties. Less than a month later, the renowned Ariete Division decimated the 3rd Indian Motor Brigade, as Rommel beat back the British 8th Army. An immense minefield prevented the Trieste Division from joining the battle, until a path through the explosive obstacle course was cleared by the Italian XX Corps. Its artillery then blasted enemy positions near Sidra Ridge, where the British 2nd and 22nd Armoured Brigades were likewise shelled with devastating effect by the Ariete Division.

Seizing the moment, Rommel spearheaded an attack through the first line of Commonwealth defense at Gazala that knocked out 100 Crusader, Matilda and Sherman tanks, and captured 3,000 POWs. Alarmed that the entire campaign might be in jeopardy, the British launched a desperate counter-offensive, Aberdeen, on 5 June, surrounding the German 15th Brigade, and threatening it with annihilation. Storming to the rescue was the Italian X Corps, which held up Commonwealth troops in the north, while French forces at Bir Hacheim were contained by the Trieste Division and German 90th Light Division. The 15th and 21st Panzer Divisions then hooked up with the Ariete Division to confront the 42nd and 7th Royal Tank Regiments, the 2nd, 4th and 22nd Armoured, 9th and 10th Indian, and 201st Guards Brigades. After an armoured assault was broken by Italian anti-tank guns at the Sidra and Aslagh ridges, the 22nd Armoured and 201st Guards Brigades were shot to pieces, as Bir Hacheim finally fell to the Trieste Division on 11 June. The Ariete Division then wheeled around in company with the 21st Panzer Division to drive off the badly battered 4th Armoured Brigade, and the Aberdeen counter-offensive fizzled. Now, the British had nothing left to stop Axis forces from going after Tobruk.

On 20 June, the rescued Deutsche Afrika Korps and Italian XX Corps engaged the city defenders in savage fighting that developed into hand-to-hand combat. The next day, Regia Aeronautica Capronis and Luftwaffe Stukas launched a massive aerial bombardment that brought Tobruk to its knees. Among the booty were thirty tanks, 2,000 vehicles, 400 artillery, 33,000 prisoners, and several thousand gallons of precious fuel. Thus re-equipped, the Italo-German armies drove at Alexandria. They overran the original British defenses at Marsa Matruh standing guard at the Egyptian frontier, then found themselves unexpectedly deadlocked with Commonwealth forces at El Alamein.

But something had changed. The British seemed to be able to read Rommel’s mind. Wherever he turned his Panzers, enemy anti-tank guns were waiting for them. He was no longer able to surprise his opponents, who seemed to anticipate his every move. Although he could not have known that enemy intelligence officers were reading all his orders and strategic plans, he did suspect either spies in the Afrika Korps or Italian turncoats were somehow getting sensitive information to the other side. The traitors, however, were not Italian, but German.

The effects of betrayal were soon in coming. Less than thirty days after Reinhard Heydrich’s assassination, the hitherto victorious Ariete Division was savaged by the combined forces of Britain’s 1st and 7th Armoured Brigades and the New Zealand Division. A week later, on 11 July, the 382nd German Regiment, together with part of the Italian Trieste and Sabrantha Divisions, was overrun. Mussolini dispatched additional Semovente anti-tank guns manned by an elite parachute division, the Folgore, the ‘Lightning’. Also known as the 18th Cacciatori d’Africa, ‘The Hunters of Africa’, they were ordered to take up positions between Deir el Munassib and the Qaret el Himeimat heights to cover Axis forces while recuperating from recent reverses at El Alamein.

Allied crypographers had yet to entirely fine-tune their so-called ‘ULTRA Secret’, however. They often lagged behind the rapid change of events which characterized desert warfare. While the Afrika Korps was still too weak for action, the Ariete, Brecia and Trento Divisions captured the Siwa oasis on 21 July. A British attack the next day failed to dislodge the Italians, who knocked out 146 tanks and took 1,400 Commonwealth prisoners.

Undeterred by these losses, the 9th Australian and 1st Armored Brigades overran the Trento’s 61st Battalion and the German 361st Regiment. Axis commanders counter-attacked with a Trento artillery barrage that blasted twenty-seven tanks, along with thirty armoured cars and trucks. A thousand Commonwealth troops surrendered. Furious shelling by the Italian XX Corps forced New Zealanders of the 22nd Armoured Brigade into a minefield, where ninety-seven Valentine tanks and 120 anti-tank guns were blown to bits. Shortly thereafter, the British tried to break through the area held by Italian paratroopers at Deir el Munassib. The 18th Cacciatori d’Africa repulsed the attacks with heavy losses to Commonwealth forces in men and armoured cars.