'Sturmflut' was the German final stage of 'Morgenluft' (i) in Tunisia by General Gustav Fehn’s Deutsches Afrikakorps to take the Kasserine Pass and open the way for an advance to Thala and Tébessa (19/24 February 1943).

This last effort was directed against the US positions in the Kasserine Pass by the assault group of the Deutsches Afrikakorps under the temporary command of Generalmajor Karl Bülowius (Fehn had been badly wounded on 15 January) under the overall leadership of Generalmajor Kurt Freiherr von Liebenstein but in fact controlled by Generalfeldmarschall Erwin Rommel, commander of the Deutsch-Italienische Panzerarmee.

The resulting Battle of the Kasserine Pass was fought in a gap, 2 miles (3.2 km) wide, in the Dorsale Occidentale chain of the Atlas mountains in western central Tunisia. The Axis forces were primarily an assault group of the Deutsches Afrikakorps, elements of Generale di Divisione Giorgio Carlo Calvi di Bergolo’s 131a Divisione corrizata 'Centauro' and two Panzer divisions detached from Generaloberst Hans-Jürgen von Arnim’s 5^th Panzerarmee against Allied forces of the Major General Lloyd R. Fredendall’s US II Corps and Major General C. F. Keightley’s British 6^th Armoured Division of Lieutenant General K. A. N. Anderson’s Allied 1^st Army.

This battle was the first major engagement between US and German forces in World War II, and the inexperienced and poorly led US troops suffered heavy casualties and were quickly pushed back more than 50 miles (80 km) from their positions to the west of the Faïd Pass, but after this initial reverse elements of the US II Corps, reinforced by the British, rallied and held the exits through mountain passes in western Tunisia, defeating the Axis offensive. The US Army then swiftly instituted sweeping changes from unit-level organisation to the replacement of commanders.

By 17 February, 'Morgenluft' (i) and 'Frühlingswind' had both achieved their primary objectives, but the opportunist Rommel now wanted to exploit the Allied evacuation of the Dorsale Occidentale by advancing through the Kasserine Pass to take Tébessa and so disrupt the rear areas of Fredendall’s US II Corps and Général de Corps d’Armée Marie Louis Koëltz’s French XIX Corps d’Armée of Anderson’s Allied 1^st Army, and then striking out toward Bône and Constantine to defeat the 1^st Army in its entirety. Rommel asked von Arnim for the co-operation of his 5^th Panzerarmee, but von Arnim responded that, while Generalleutnant Friedrich Freiherr von Broich’s 10^th Panzerdivision and Generalleutnant Hans-Georg Hildebrandt’s 21^st Panzerdivision were under Rommel’s control for the operation, he believed that the best course was now an advance farther to the north-west against Le Kef with a view to an exploitation from the Medjerda river toward Béja. A third view in the matter was that of the Italian Comando Supremo, which on 19 February ordered that Rommel’s combined force should strike to the north with the object of cutting off Lieutenant General C. W. Allfrey’s British V Corps or at least of driving it back to the Algerian frontier.

Generalfeldmarschall Albert Kesselring, the Oberbefehlshaber 'Süd', considered the advantages and disadvantages of all three plans. In general Kesselring preferred that of Rommel, which he submitted to the Comando Supremo with his endorsement on 18 February. At 13.30 on the following day, Rommel received the Commando Supremo’s agreement to a revised plan. He was to receive the 10^th Panzerdivision and 21^st Panzerdivision from the 5^th Panzerarmee, which in fact released only a Kampfgruppe under von Broich’s command, and attack through the Kasserine and Sbiba passes toward Thala and Le Kef to the north, clearing the Dorsale Occidentale and threatening the 1^st Army’s flank.

Rommel was appalled, for the revised plan dispersed the Axis forces and movement through the passes would expose their flanks. A concentrated attack on Tébessa, while entailing some risk, could yield badly needed supplies, destroy Allied potential for operations into central Tunisia and capture the airfield at Youks les Bains, to the west of Tébessa.

In fact Rommel had already decided to pre-empt any decision from higher command echelons and began 'Sturmflut' at 04.50 on 19 February, moving out from Kasserine, which had been reached on 18 February as the culmination of 'Morgenluft' (i). Rommel planned to use his well-proved tactics of speed and movement with comparatively small forces, totalling some 22,000 men, to ensure success against a 30,000-man opposition in considerable command and tactical disarray as a result of 'Morgenluft' (i) and 'Frühlingswind'. Such a move was well within the capabilities of the Deutsches Afrikakorps' assault group, which was to be reinforced after it had taken the Kasserine Pass by the 10^th Panzerdivision diverted from the Fondouk region on 19 February.

In the early hours of February 19, Rommel ordered the assault group of the Deutsches Afrikakorps to advance from Fériana toward the Kasserine Pass, and at the same time the 21^st Panzerivision at Sbeitla was ordered to attack to the north through the pass to the east of Kasserine which led to Sbiba and Ksour. The Kampfgruppe 'von Broich', the battle group released by von Arnim from the 10^th Panzerdivision, was ordered to concentrate at Sbeitla, where it would be ready to exploit success in either pass.

Facing the German armoured advance in the Sbiba area was the British 6^th Armoured Division less Brigadier C. A. L. Dunphie’s 26^th Armoured Brigade which, with the exception of the tanks of the 16^th/5^th Lancers, had been sent to Thala. Also in the line was the 18^th Regimental Combat Team of Major General Terry de la M. Allen’s US 1^st Division and three battalions of Major General Charles W. Ryder’s US 34^th Division. There were also three US field artillery battalions, elements of two British anti-tank regiments and some French detachments. The 21^st Panzerdivision made little progress against the combined firepower of the defending force, which had also laid minefields. The 21^st Panzerdivision was checked and had been driven back by 20 February.

Defending the Kasserine Pass was a force comprising the US 1/26^th Regimental Combat Team, US 19^th Combat Engineer Regiment, US 6^th Field Artillery Battalion, one US tank destroyer battalion and one battery of French artillery. On the hills to this force’s west was Général de Division Marie Joseph Edmond Welvert’s Task Force 'Welvert' comprising one US Ranger and one US infantry battalion, three French infantry battalions, two US field artillery battalions, four French artillery batteries and engineer and anti-aircraft detachments. Farthest to the west was Lieutenant Colonel John W. Bowen’s Task Force 'Bowen', comprising the 3/26^th Regimental Combat Team, blocking the track from Fériana towards Tébessa. Between Task Force 'Bowen' and Tébessa, to the north, was the regrouping Major General Orlando Ward’s US 1^st Armored Division, of which only Combat Command B was ready for operations. During the night of 18/19 February, the positions in the Kasserine Pass had been placed under the control of Colonel Alexander N. Stark, commander of the 26^th Regimental Combat Team, whose command was thereupon designated as 'Stark' Force with the 1/26^th Infantry, elements of the 19^th Combat Engineers, the 33^rd Field Artillery Battalion, the 805^th Tank Destroyer Battalion, and the French 67^th African Artillery Regiment.

An attempt by Hauptmann Detlef von Lienau’s 33^rd Aufklärungsabteilung of the 15^th Panzerdivision to surprise the Allied defences in the Kasserine Pass with a swift penetration was unsuccessful and single Panzergrenadier battalions were ordered into the floor of the pass and onto the Djebel Semmama, the hill on its north-eastern flank, and slow progress was made against artillery fire. The tanks of the 1/8^th Panzerregiment were committed at 12.00 but made little further progress against stubborn defence. Rommel decided to commit his units from the 10^th Panzerdivision to the Kasserine Pass during the morning of the following day in a an attack co-ordinated with that of the Deutsches Afrikakorps' assault group, which was to be joined by elements of the 131a Divisione corazzata 'Centauro'. British reinforcements of the 26^th Armoured Brigade had meanwhile been assembling at Thala, and after making a personal reconnaissance, Dunphie decided that the time was right for an intervention. The 1^st Army headquarters, however, was not so sure and restricted Dunphie to sending 'Gore' Force, which was a small combined-arms group with one company of infantry, one squadron of 11 tanks, one battery of artillery and one anti-tank troop. At this time Brigadier C. G. G. Nicholson, the deputy commander of the 6^th Armoured Division, was given command of 'Nick' Force, which comprised all the units to the immediate north-west of the pass.

During the first night of its defence of the Kasserine Pass, 'Stark' Force was reinforced by one battalion of the 6^th Armored Infantry and part of the British brigade rushed forward from Thala. This mix of miscellaneous units was wholly inadequate for the task of checking a Deutsches Afrikakorps assault group reinforced by part of the 10^th Panzerdivision, which in the course of the night overran the US positions on the two shoulders overlooking the pass, and at 08.30 German Panzergrenadiers and Italian Bersaglieri resumed the attack. At 10.00 Dunphie judged that 'Stark' Force was about to give way and ordered Lieutenant Colonel A. C. Gore’s 'Gore' Force to the Thala side of the pass as elements of the 131a Divisione corazzata launched their attack toward Tébessa and continued it during the afternoon. At 13.00 Rommel committed two battalions of the 10^th Panzerdivision, and these overcame the US defence. Tanks and Bersaglieri of the 131a Divisione corazzata advanced along Highway 13 and overran the 19^th Combat Engineer Regiment. The US survivors made a disorganised retreat up the north-western exit from the pass toward the Djebel el Hamra, where the 1^st Armored Division’s Combat Command B was now arriving. On the exit to Thala, the 'Gore' Force slowly fell back in a series of leapfrog movements, losing all its tanks in the process, to rejoin the 26^th Armoured Brigade some 10 miles (16 km) farther to the rear.

In the Djebel el Hamra area, the Deutsches Afrikakorps' assault group began to advance along the Hatab river valley towards Haidra and Tébessa early in the afternoon of 21 February, advancing until it met a defence found by the 16^th Infantry of the US 1^st Division and Combat Command B of the US 1^st Armored Division at the Djebel el Hamra. Here the German and Italian force was checked and, despite its heavy pressure well supported from the air, failed to dislodge the US defenders. Having brought the Axis drive towards Tébessa to a halt, Brigadier General Paul McD. Robinett’s Combat Command B and Allen’s US 1^st Division now turned their attention to planning a counterattack for the following day. Plans made by both sides were upset by the nature and results of the ongoing battle, however, and the Axis forces launched another assault on the US position on the morning of 22 February. Although the US forces faced considerable pressure, they held their line and by the middle of the afternoon the US infantry and armour were able to launch a counterattack which broke the German and Italian force. The US forces took prisoner more than 400 Axis troops as the counterattack was pressed into the Deutsches Afrikakorps' position.

Rommel had remained with the main group of the 10^th Panzerdivision on the route toward Thala, where the British 26^th Armoured Brigade and remnants of the US 26^th Infantry had dug themselves into defensive positions on ridges. If the town fell and the southern of the two roads from Thala to Tébessa was cut, Major General Manton S. Eddy’s US 9^th Division to the north would be cut off and Combat Command B of the 1^st Armored Division would be trapped between the 10^th Panzerdivision and its supporting units as they moved to the along the second road to Tébessa. The combined force fought a costly delaying action in front of Thala, retreating ridge by ridge to the north, and by the fall of night had managed to halt the German attacks just to the south of the town. The 48 pieces of artillery fielded by the 9^th Division’s divisional artillery and anti-tank platoons, which had moved to the east from Morocco, some 800 miles (1285 km) on 17 February, dug in during that night. On the next day, the front was held mostly by British infantry, with exceptionally strong backing by unified US and British artillery, under Brigadier General Stafford LeR. Irwin, the US artillery commander. The British had 36 guns, supported by the Derbyshire Yeomanry and the 17^th/21^st Lancers.

Anderson ordered the 9^th Division and its artillery support to Le Kef to meet an expected German attack but Major General Ernest N. Harmon, who had been sent by General Dwight D. Eisenhower, commanding the US North African Theater of Operations, to report on the battle and the Allied command, instructed the 9^th Division’s divisional artillery to remain behind. On the morning of 22 February, an intense artillery barrage delivered by the massed Allied guns forestalled the resumption of the 10^th Panzerdivision's attack, destroying armour and vehicles and disrupting communications. von Broich, the Kampfgruppe commander, decided to pause and regroup, but Allied reinforcements continued to arrive and, under constant fire, the 10^th Panzerdivision waited until the fall of night to retire from the battlefield.

Overextended, its supplies now dwindling rapidly, pinned down by the Allied artillery in the pass in front of Thala and now facing US counterattacks along the Hatab river, Rommel realised that his attack had been stopped. At Sbiba, along the Hatab river and now at Thala, the efforts of the German and Italian forces had failed to effect a decisive breakthrough of the Allied line. With little prospect of further success, Rommel therefore decided that it would be wiser to break off and thus be able to concentrate in southern Tunisia and strike a blow at General Sir Bernard Montgomery’s 8^th Army, catching this off balance while it was still assembling its forces. Rommel at least had the consolations that he had inflicted heavy losses on his opponents and that the Allied concentrations in the area of Gafsa and Sbeitla had been destroyed. At a meeting held in Rommel’s headquarters at Kasserine on 23 February, Kesselring and his operations officer, Oberst Siegfried Westphal, tried to change Rommel’s mind, arguing that success was still possible, but Rommel was adamant and Kesselring finally agreed and formal orders from the Comando Supremo in Rome were issued during the evening of the same day to end the offensive and direct all Axis units to return to their start positions.

On 23 February a major US air attack on the pass hastened the German retreat, and by a time late on 24 February US forces had reoccupied the pass, Fériana was in Allied hands, soon followed by Sidi Bou Zid and Sbeitla.

'Sturmflut' was over, the day for such extemporised forays with limited matériel and fuel resources being long past. The Battle of the Kasserine Pass had cost the Allies some 10,000 casualties (including 6,500 US) as well as 183 armoured fighting vehicles and 706 trucks, while the Axis forces had suffered about 2,000 casualties and lost 34 armoured fighting vehicles.

Rommel had hoped to exploit the inexperience of the new Allied commanders, but had been opposed by von Arnim, who wished to conserve strength in his sector, ignored Kesselring’s orders and withheld the attached heavy tank unit of the 10^th Panzerdivision. Rommel felt that most US units and commanders had revealed their inexperience as their focus tightened on the narrower rather than broader picture. Rommel was unable to undertake a major exploitation of the Allied failings as a result of a shortage of strength and limited freedom of manoeuvre, and thus missed a significant opportunity. Nonetheless he was generous in his praise of the 2/13^th Armored Regiment of the 1^st Armored Division in the defence of Sbeitla, which he characterised as clever and well fought.

Rommel was later impressed by the speed with which US commanders came to understand and implement mobile warfare, and also praised US equipment, in which he felt British experience has been put to good use. Of particular interest to the Germans was the M3 armoured half track and for some time after the battle, German units deployed large numbers of captured US vehicles.

The nature of the battle was studied just as seriously by the Allies. Positioned by senior commanders, most especially Fredendall, who had not personally reconnoitred the ground, the US forces were often deployed too far from each other for the provision of any type of effective mutual support. It was also noted that US soldiers had developed a tendency to dig in effectively, to expose their positions, to bunch in groups within open view of German and Italian artillery observers, and to position units on topographic crests, where their silhouettes made them perfect targets. Many soldiers had clearly been too unwilling, in Tunisia’s rocky terrain, to excavate deep foxholes and had therefore created nothing more than shallow slit trenches which provided little, if any, protection against artillery and machine gun fire. It also appeared that the 1^st Armored Division had not been prepared to digest the implications of British experience on how to handle German anti-tank and screening tactics. The Allies had also not prevented the Germans from attaining air superiority over the battlefield, a fact which limited the efficiency of Allied air reconnaissance and allowed the Germans to fly relentless bombing and strafing attacks, which disrupted Allied attempts at deployment and reorganisation. Moreover, Luftwaffe attacks in close support of German ground movements often neutralised US attempts to organise effective defensive artillery fire.

Eisenhower began to restructure the Allied higher command, creating the 18^th Army Group under the command of General the Hon. Sir Harold Alexander to tighten the operational control and improve the co-ordination of the three Allied nations involved. Fredendall was relieved and sent home. The custom among theatre commanders of relegating senior commanders who had failed in battle to training commands at home did not improve the reputation or morale of such commands, which felt that they had been placed in the hands of disgraced commanders reluctant to advocate radical improvements in training programmes which, like the commanders, had been a major contribution to the US reverses in North Africa.

Eisenhower found through several senior officers, including Major General Omar N. Bradley, his personal representative in the field, that Fredendall’s subordinates had already lost confidence in him, and Alexander told some US commanders that he was sure that they must 'have better men than that'.

While Fredendall took the major portion of the blame for the defeat in the Karrerine Pass, the commander of the Allied 1^st Army, Anderson, was also judged to be at fault for his failure to impose any concentration on the Allied armoured units and to integrate formations which then disintegrated into disjointed units. When Fredendall disclaimed all responsibility for the poorly equipped French XIX Corps and denied French requests for support, notably when under pressure at Faïd, Anderson allowed the request to go unfulfilled. Anderson was also blamed for dispersing the three combat commands of the 1^st Armored Division, despite the objections of Ward, the divisional commander. Irwin became the successful commander of the US 5^th Division and later of the US XII Corps, and Nicholson became commander of the Indian 44^th Armoured Division and, in Burma, of the Indian 21^st Division and British 2^nd Division.

Henceforward, Allied commanders were given more opportunity to use their initiative, make their own decisions and keep their forces concentrated. They were also urged to lead their units from the front, and to keep command posts well forward, unlike Fredendall, who had rarely visited the front line.

On 6 March, Major General George S. Patton was diverted, on a temporary basis, from planning for the Allied 'Husky' (i) invasion of Sicily to command the US II Corps. Bradley was appointed assistant corps commander and then to command of the II Corps when Patton returned to planning for the Sicilian campaign, in which led led the US 7^th Army. Like Fredendall, several other commanders were removed or promoted out of the way. Patton was not known for hesitancy and did not bother to request permission when taking action to support his command or other units requesting assistance. During the advance from Gafsa, for example, Alexander had given detailed orders to Patton, afterwards changing II Corps' mission several times. Once beyond Maknassy, Alexander again issued orders which Patton considered to be too detailed, and from this time onward Patton simply ignored those parts of his instructions which he believed to be ill-advised on grounds of military expediency and/or a rapidly evolving tactical situation.

Efforts were also made to improve the integration of immediate artillery and air support, which had been poorly co-ordinated. While US artillery response times was improved significantly and in a short period, the co-ordination of close air support was not fully achieved until the 'Overlord' invasion of France more than two years later. The US anti-aircraft artillery was also launched into a reorganisation effort after it had been learned the hard way that while Junkers Ju 87 dive-bombers were vulnerable to 0.5-in (12.7-mm) heavy machine gun fire from the ground, ion overall terms field units and field artillery needed superior protection from air attack: in one division, 95% of air attacks were concentrated on its artillery.

Considerably greater emphasis was also placed on keeping units concentrated, and the II Corps began to use divisions as such rather than divide them into smaller forces, and by the time of the 'Husky' (i) invasion of Sicily, the US forces were considerably more cohesive and therefore tactically stronger.