On 1 November 1927, he was promoted to Hauptmann and named the commander of the 2nd company and welfare-officer of the 1st pioneer battalion, in which he served until 1 October 1930 when transferred into the 16th mounted-regiment while detached to the Chief of the Troop Office due to his earlier high performance in the Wehrkreis exam and was selected as a candidate for the General Staff.

While Germany was planning to invade Britain in Operation Sea-lion, Gause served as the chief of staff of XXXVIII Army Corps, then commanded by Erich von Manstein, from 1 October 1940 to the end of 30 January 1941.

He privately discounted the plan as unlikely to succeed, that in spite of Göring’s optimism on air support, the Kriegsmarine was unable to defeat the powerful British Navy and would only result in “complete destruction.”[4] Gause was initially sent to Africa by the OKH on 1 June 1941.

[8] Challenges were evident in the overall command structure of the Axis office politics, but Gause was not a complainer and acted with a military aspect, trying his best to adapt to the unorthodox method of Rommel.

During the attack on Got-el-Ualeb in the Battle of Gazala on 1 June, Gause was nearly hit by a British antitank round but was hurled backward and landed on the ground with a serious brain concussion with shrapnel wounds.

Its commander Rommel was recalled involuntarily to Europe on 9 March 1943, whilst Generaloberst Hans-Jürgen von Arnim succeeded and Gause remained the chief of staff.

To defend the upcoming Allied invasion in the Mediterranean, on 20 May he was detached to a special staff of Rommel for the planning and execution of Operation Alarich, the disarm and occupation of North Italy.

Based on the experiences in the southern theatre, Gause had also emphasized on the necessity of quick action in the case of a landing, clarifying that the army group did not intend to “tie down” the mobile units and guaranteed the flexibility.

[11] He was relieved on 15 April 1944, where Rommel again praised his organizational and tactful talents with a hardness on himself, but hesitated on his future performance under heavy pressure, specifically referring to the unhealed concussion in the Battle of Gazala.

[15] Gause was then put in reserves for two months until the appointment on 15 June to Panzergruppe West, later renamed the 5th Panzer Army, that participated in the retreat of German forces in France.

[16] In mid-August, Gause successfully got the men and all the important fighting vehicles to the opposite bank when the Allies did not immediately attack with the anticipated strength against the German position near the Risle River, although the equipment losses were heavy.

[17] After the Allied had run over the Kitzinger Line on 31 August, Sepp Dietrich expressed his doubts and merely told Gause to give up the constant attempt to establish contact with the subordinate troops.

[18] On 1 September, when Walter Model ordered the 15th Army and 5th Panzerarmee to prevent the total annihilation of the pushed 15th Army by closing the frontline, Gause referred the order as a mere “war diary order.” He stated that “there was no normal front line anymore”, where the units were no longer units, cannot “be given any impossible orders.” His blunt words described the shattered condition of the Western Front.

During the postponement of the later Ardennes counter-offensive from 20 October to 10 December for extra preparation, on 20 November, Hitler ordered Fritz Kraemer to take over Gause as Dietrich's chief of staff with no given explanation.

Brennecke, after the third course for commanding generals and corps chiefs, commented Gause with a "distinct East Prussian tribal stamp", and approved his decision-making skills as clear and firm.