The Germans began the war with illdefined war aims, beyond domination of Euroope. Exactly what that meant was open to interpretation.
I believe that to understand German war aims , one has to try and get into the mind of Hitler. Hitler was not an idiot, in fact I think he was a psychopath, which is a criminal with a genius like malevolence. Hitlers war aims were related to his personal demons. He wanted to avenge the "betrayal of WWI", and the carnage of the westrern front. So in the first instance he persecuted the Jews, then exterminated them, because he believed they had been instrumental in orchestrating Germany's defeat. He wanted to defeat and humiliate the french, which he achieved. He had assumed that with France knocked out, the British would also capitulate and become his sex toy....didnt work, thanks to the BoB.
He could not understand why the british would continue to fight when defeat of Germany was not possible in the conditions that existed in 1940-41. He assumed the US would stay neutral, and knew the British could not undertake a continental campaign on their own. He reasoned that they must be looking for a new continental ally, and the only available candidate was Russia. Since russia was also communist, and Hitler was rabidly anti-communist, he saw an opportunity to kill three birds with one stone....complete the isolation of the british, destroy the birthplace of the hated communists, and gain control of the resources and open spaces of the east. To us, it should be meglomaniacal claptrap, but to a mind like Adolph Hitlers, it made perfect, logical sense. And he had plenty of supporters within Germany who saw his logic as impeccable (there are many who still support his crackpot theories). Many, if not most German officers were enthusiastic supporters of the invasion of Russia. So the invasion went ahead.
At first things went ahead swimmingly. City after city fell, vast quantieis of booty and prisoners were captured, vast areas of territory captured. Then the winter hit, and the russians, thought to be on their knees militarily, counterattacked, destroying large sections of the front. The Germans, and Hitler were shaken. The generals started to go to water and wanted to withdraw completely, Hitler on this one occasion acted more rationally even though he was onoly acting on instinct himself. If the german army had retreated as the Genmeral Staff had wanted, most of the german army would have been destroyed in the retreat....they were too immobile in the winter to withdraw effectively. Hitler, acting on his instincts, ordered that the army stand fast and fight. And though heavy losses were incurred in meeting that order, it also blunted the Soviet reserves and in so doing achieved the survival of a portion of the wehrmacht.
The German emerged from the winter of 1941 with much reduced offensive capability. No longer were they able to attack along the entire front, they had sufficient tanks, aircraft, manpower and transport to attack with one of the army groups available (of three). The Soviets had suffered a heavy final defeat at Izyum and Kharkov, losing most of their tanks in an illconsidered offensive, and this gave opportunity for the germnans to attack. Within a month they were commencing their own attacks.
Hitler paused, hesitated and reconsidered his war aims. ever the opportunist he was savvy enough to know that the full conquest of European SSRs was now beyond his capability. But he reasoned that by securing the Caucasian Oil and denying it to Russians he could deal an economic blow to the russians that they could not recover from. Funnily enough this was a view largely shared by his enemies. STAVKA received a report in 1942 that predeicted that if all the
Trans-caucasian oil was lost, Soviet military production would drop by more than 60%. A linchpin in the capture of the Caucasus was the capture of Stalingrad.
In 1942 there were several overtures for peace put out by the Russian and the germans, but they came to nothing. Both sides believed they could win.
Even though on paper, the german Case Blau made good sense, in reality it was a fatally flawed plan, and many german officers knew it. It would further extend already overstretched German supply lines. There were insufficient troops and equipment to complete both objectives. The Russians had learnt a lot from the previous defeats. Halder was against the plan as was Rundstedt, and a number of other officers. Halder attempted to persuade the fuhrer not to undertake the offensive but hitler would not listen.
For rommels plan to work (which in any case was not developed until '43), Hitler would have needed to be persuaded either to relinquish direct control of the army (see below), or agree not to embark on major offensive operations in 1942 and/or 1943.
There was another opportunity to inject sanity into wehrmacht operations. Following the debacle at Stalingrad, there were mooted suggestions that the control of the army on the east Front be passed back to a serving officer, with the suggested obvious choice being Manstein. like the ceasefire feelers, these suggestions came to nothing....but they raise an intersting "what if"
So we have two likley alternatives to this scenario....either a defensive stance from 1942, or a general put incharge in 1943. If either of these strategiers had been put in place, what would be the possibilities that could arise. Could sufficient casualties be inflicted on the Russians to force them to the peace table or at lease to halt their offensives?