Although Hitler was opposed to unnecessary retreats, von Manstein recognized that the hidden benefit of retreating toward the Donets and Rostov was that German supply lines were shortening and it was becoming easier to bring reinforcements into battle by rail, whereas Vatutin’s supply lines were stretched to the breaking point and getting worse as they moved westward. Nevertheless, von Manstein’s Heeresgruppe Don was under great pressure in the centre and on both flanks and one mistaken command decision could lead to a disastrous encirclement; the only factor that blocked Vatutin from swiping the bedraggled units of Gruppe Hollidt out of his way was a handful of battle-worn Panzer-Divisionen and a single Panzer-Abteilung.
At the start of January, Gruppe Hollidt had established a porous HKL along the Taymbiya River, with von Knobelsdorff’s XXXXVIII Panzerkorps holding the northern shoulder, Generalmajor Dietrich von Choltitz’s XVII Armeekorps in the centre and Armeekorps Mieth holding the right flank on the Don. The German front suffered from a lack of quality infantrymen and two Luftwaffe Feld-Divisionen were committed into the centre. Flak units were also inserted into the frontline, using 2cm, 3.7cm and 8.8cm guns in the direct-fire role. A few surviving Romanian battle groups were still at the front, but their combat value was minimal. Hollidt’s three Panzer-Divisionen were a mixed bag; General-major Erhard Raus’ 6.Panzer-Division was down to about 40 tanks, including 4–5 Pz IVs with long 7.5cm guns, but was still full of fight. Hollidt used Raus’ division as the core of XXXXVIII Panzerkorps. Oberst Eberhard Rodt’s 22. Panzer-Division, which was attached to the XVII Armeekorps, had been virtually demolished during Operation Uranus and von Manstein described it as ‘a complete wreck’; by January, the division had been reduced to a regimental-size Kampfgruppen with no more than a dozen tanks.{26} Hollidt kept Balck’s still effective 11.Panzer-Division in reserve to deal with any Soviet breakthroughs; this division had 32 tanks, including three Pz IV with long 7.5cm guns.{27} It is noteworthy that the Pz III with long 5cm gun remained the principal German battle tank in the winter battles and how only token numbers of Pz IVs participated in these crucial battles.
Flushed with success from Operation ‘Little Saturn,’ Vatutin’s Southwest Front was presented with a multitude of options because the enemy was weak in so many sectors. Although Vatutin concentrated General-leytenant Markian M. Popov’s 5th Tank Army and the General-leytenant Dmitri D. Lelyushenko’s 3rd Guards Army (3 GA) against Gruppe Hollidt, he directed General-major Vasily I. Kuznetsov’s 1st Guards Army (1 GA) to crush Armee-Abteilung Fretter-Pico. Vatutin was one of the Red Army’s best front commanders but he was attempting to mount two simultaneous major parallel operations, which strained Soviet C2 and logistic capabilities. Furthermore, most of Vatutin’s mechanized units were in poor condition after six weeks of continuing combat and had less than half their tanks still operational. The two tank corps that had conducted the raids against Tatsinskaya and Morozovskaya airfields on 17–28 December 1942 – Badanov’s 24th Tank Corps and Popov’s 25th Tank Corps – were reduced to wrecks. Rather than pull them out to rebuild in the RVGK as was standard, the Stavka ordered them to remain with Lelyushenko’s 3 GA and they were combined with the equally mangled 1st Guards Mechanized Corps. Vasiliy M. Badanov, who had angered Stalin by his unauthorized withdrawal from Tatsinskaya, was put in charge of this agglomeration of wrecked units; in his memoirs, Badanov noted that these three corps had barely 50 tanks left between them and very few trucks or infantry.{28} Consequently, Vatutin’s best field commander – Lelyushenko – was left with very few tanks to support the advance of 3 GA. Popov’s 5th Tank Army (5 TA) still had two tank and mechanized corps with roughly 200 tanks left and it was supposed to be Vatutin’s spearhead, but its performance had been disappointing since the fighting on the Chir River. A large part of the problem was Popov himself, who was a drunk and frequently negligent commander. Eventually, he would be relieved of command for his failings, but in an army that was quick to punish officers, Popov was tolerated for far too long. Even when sober, he was the wrong sort to command a tank army, since he had a linear, set-piece approach to warfare that was not unlike Bernard Montgomery’s. Popov was content to use his superiority to gradually shove Gruppe Hollidt rearward, rather than conduct anything too daring. The recent fate of the 24th and 25th Tank Corps’ Deep Operations likely also dissuaded Popov from trying to go deep, even though Hollidt’s right flank was little more than a screen.
In order to achieve decisive success in war, particularly mobile warfare, one must be willing to take risks, but it takes a combination of experience – and luck – to know when the risks become unacceptably dangerous. German panzer commanders had figured this dynamic out in 1941–42 and often managed to made it work for them; in the post-Stalingrad hubris Vatutin believed that he could accomplish this feat as well, although the tools and subordinates available were not up to the task.
Gruppe Hollidt’s main position was near the airfield at Morozovskaya, on the main rail line to Stalingrad, which was held by the remnants of the 22.Panzer-Division and the 7. and 8.Luftwaffe Feld-Divisionen. Vatutin attempted a pincer operation against this strongpoint, attacking from the north with Badanov’s ad hoc armoured group and from the east with General-major Mikhail D. Borisov’s 8th Cavalry Corps and some of Popov’s armour. Considering the poor quality of the defence, Popov’s 5th Tank Army should have simply rolled over the two inexperienced Luftwaffe divisions, but instead it merely pushed them back and the 22.Panzer-Division abandoned Morozovskaya on 4 January. South of Morozovskaya, Eremenko had sent the 1st Guards Rifle Corps from 2 GA across the Don to push in Hollidt’s right flank near Tsimlyansk and Hollidt was obliged to commit Balck’s 11.Panzer-Division to prevent this flank from collapsing. Meanwhile, Lelyushenko’s 3rd Guards Army was gradually overcoming the XXXXVIII Panzerkorps and the commitment of General-major Efim G. Pushkin’s refitted 23rd Tank Corps from front reserve threatened to break Hollidt’s left wing, so von Manstein decided to send the fresh 7.Panzer-Division to reinforce von Knobelsdorff’s sector.
Generalleutnant Hans Freiherr von Funck’s 7.Panzer-Division began detraining near Kamensk on 5 January and brought 91 Pz III Ausf L/M, 14 Pz III Ausf N and 18 Pz IV Ausf G, as well as a company of Marder III Panzerjäger. In addition to the welcome addition of the full-strength Panzer-Regiment 25 with two battalions, von Funck’s 7.Panzer-Division brought four fresh Panzergrenadier-Bataillonen into the fight, including one equipped with SPWs. Less than 48 hours after detraining, the lead Kampfgruppe from 7.Panzer-Division marched eastward to confront Pushkin’s 23rd Tank Corps, which was shoving its way past the depleted 6.Panzer-Division’s left flank. Like the proverbial cavalry arriving in the nick of time, von Funck’s veteran panzers halted the Soviet armoured advance in a series of tank battles fought on the steppes amid swirling snow showers. Lelyushenko’s 3rd Guards Army was brought to a screeching halt. However, Hollidt had to commit all his available armour to hold both his left and right flanks, leaving only the threadbare 22.Panzer-Division to hold the centre. After halting Vatutin’s offensive for a week, Hollidt finally gained permission to withdraw behind the Donetsk River on 15 January and by the night of 16–17 January all his forces had established a more compact and solid HKL on the western bank.