German military historian Karel commented on the two phases of the Soviet-German war: "Germany's (probable) victory ended in Stalingrad ahead of schedule, while Germany's defeat began in Kursk", which is infinitely close to accurate.
So, the German army did not suffer a crushing defeat like Stalingrad in the Battle of Kursk, and no army group or even corps-level formation was completely annihilated by the Soviet army, so why did it collapse from then on to the collapse of the entire Eastern Front?
The most technical military terminology answered: the complete loss of the strategic reserves of the German army.
In fact, this is also the main reason why the front-line generals Manstein and Kruger to the German Army General Staff in the rear did not support Hitler's launch of the "Bastion Operation", and these veteran commanders who had fought with the Soviet army for nearly two years saw the situation on the Eastern Front very clearly: If the German army wanted to inflict heavy losses on the Soviet army and force it to withdraw from the war or negotiate peace, the only correct tactic was to hold the strategic reserves that had been accumulated with great difficulty in their hands, and to attack head-on in a certain strategic direction in which the Soviet army might launch an offensive.
In order to understand the tactical theories of Manstein and his ilk, you must first understand the Soviet-German battlefield situation before the Battle of Kursk, in which the Germans suffered heavy losses in the Battle of Stalingrad that ended in early 1943, but Manstein used the victory in the Third Battle of Kharkov to halt the Soviet army's advance.
With the arrival of the muddy period of the Soviet Union, the two sides once again formed a frontal confrontation, as in the spring of 1942. This north-south front, which stretched from Leningrad to the Crimea, was flanked by the largest warring army in human history, with a total number of more than 12 million troops.
In that year, Germany began to mobilize for the war, and 2 million new recruits were again conscripted, so that despite the loss of troops at Stalingrad, the German army on the Eastern Front still reached a peak of 3.3 million field army strength, even more than the number of 3.2 million when the "Barbarossa Plan" was implemented in 1941, and because Finland had not yet withdrawn from the war, there were still 1.5 million client state troops fighting with the German army. After continuous mobilization and replenishment, the Soviet army already has 6.6 million field troops on the battlefield.
We know that as a result of comprehensive consideration of the combination of weapons and people, training and will, the average quality advantage of the German army should be about 2 to 1, that is, one German soldier can almost deal with two Soviet troops. If the ratio of German battlefield forces is greater than this value, the German army has the ability to gain the strategic initiative, and if it is less than this value, then the German army will be crushed by the numerical superiority of the Soviet army, which is indisputable.
Roughly calculated, the Soviets had to allocate 1 million troops to deal with the poorer armies of the client states, and about 5.6 million were able to confront the Germans.
If the balance of power and stability of the front is maintained, according to the quality gap of 1 to 2, the German army only needs to maintain a field army of 2.8 million on the front line, so that it can free up about 500,000 strategic reserves, especially most of the rapid divisions (Panzer Division, Panzergrenadier Division and Motorized Division), so as to become the most elite strike force of the German army.
Therefore, Manstein's tactical theory is to make full use of these 500,000 elite troops to carry out fierce counter-assault and anti-encirclement in the possible offensive direction of the Soviet army, so as to annihilate the living forces of the Soviet army as much as possible in mobile operations. Unfortunately (forgive me for saying this), Hitler's concept of "we always strike first" killed the German Army, and the commander-in-chief of the army had to strike first as long as he had a little bit of a gamble in his hand.
And this so-called "gamble" is not to recruit hundreds of thousands of new people, not to produce thousands of combat vehicles, not to build thousands of aircraft, but to assemble and mobilize these 500,000 strategic reserves, the core assault force of the German army on the Eastern Front. Under the influence of his gambler's mentality, he finally rejected the proposal of the front-line generals and insisted on launching the Battle of Kursk.
Why was the German army bound to be defeated at Kursk? Or to put back the quality and quantity problems of the front, due to leaks and other reasons, the Soviet army had a complete grasp of Hitler's campaign concept of trying to flatten the Kursk salient, so the 2.5 million troops of the Central Front, the Bryansk Front, and the Voronezh Front were concentrated in advance in this area, and the Germans had to mobilize more than 1.25 million troops even if they wanted to draw a draw. However, the fact is that Hitler, who was still in the dark against the Soviet troops, was only able to concentrate a total of 900,000 troops of Army Group South and Army Group Center.
Why did the German army completely lose the strategic initiative from then on? Because in the Battle of Kursk, the German army lost more than 500,000 men and horses, and all of them were the most elite fast troops, more than a dozen panzer divisions and panzergrenadier divisions (mechanized divisions) of Moder and Hort were basically disabled, and by the end of 1943, the German army on the Eastern Front had completely annihilated 56 divisions and severely damaged 162 divisions, irretrievably losing a large number of experienced officers and men, and the total strength had dropped to more than 2.8 million. And this loss is irreparable by Germany in any case, its mobilization capacity has reached its limit.
According to Zhukov's records, the German army lost 1,500 combat vehicles in the Battle of Kursk, including a large number of Tiger and Leopard, and also lost 3,700 combat aircraft and 3,000 artillery pieces, but in 1943-1944, Germany's military production also reached a peak, and it was still capable of replenishing the battle losses of these technical weapons.
The reason why the elite armored corps of the Wehrmacht and the SS on the Eastern Front were difficult to recover after the Battle of Kursk was that they lacked soldiers and non-commissioned officers who could master weapons proficiently, not those newly manufactured weapons, and the existence of a large number of "battle groups" was precisely because the Germans were exhausted in terms of troop replenishment.
At the same time, Hitler transferred part of the Eastern Front to reinforce the Italian battlefield, and the German field army on the Eastern Front no longer even existed in the size of 2.8 million, while the Soviet army, although it also lost 800,000 troops in the Battle of Kursk, quickly completed the replenishment, and by the autumn of 1943 it still recovered to the size of 6.6 million, and the combat experience and self-confidence of generals, officers and soldiers were greatly improved, far from being comparable to 1941. Got it?
After the Battle of Kursk, the German army was only able to maintain a leaky front on all sides, and was no longer able to organize an effective counter-assault, let alone organize a large-scale offensive, and the initiative on the battlefield had been ceded.
Now it is the turn of the Soviet army to gather mobile forces on either side and carry out large-scale offensive campaigns, always with an absolute superiority of forces to encircle the German army in front of them, but the Germans have no way at all, because there is a turnip and a pit on the battlefield, and there is no elite reserve available, so they can only be passively beaten and broken by the Soviet army.
From the moment the Dnieper defense line was broken through, the German army had in fact entered a period of collapse, the so-called clever woman could not cook without rice, and individual or partial tactical victories could not reverse the general trend of the entire war, and the only thing Hitler could do was to "dig up the sores and mend the flesh" and try his best to delay the advance of the Soviet army.
In the "Ten Strikes" of the Soviet Army later, as more German formed units were completely annihilated, the gap in strength on the Eastern Front was magnified geometrically.