I've cited it elsewhere before but while using it in another site
it occurred to me this article has some important citations useful for looking at this what if:
Because of the massive casualties the Germans inflicted during Barbarossa (by February 1942, the Red Army had lost over 3 million men captured by the Germans, and another 2,663,000 killed in action) and the huge population centers lost to the Germans the Soviet industrial labor force fell from 8.3 million people in 1940 to 5.5 million people in 1942. This also impacted the Red Army. September 1942 estimates done by E.A. Shchadenko (the man responsible for creating new Red Army units) found that more than five and a half million military age men had been lost from Red Army usage due to the German occupation of Soviet western territories. This meant that list strength of rifle divisions fell from a pre-war total of 14,483 men to 11,626 men in December of 1941. Though many point to the Soviet Union's huge size as the major impediment to any chance of German success in the war this misses a number of crucial points. Not least of which is that the Red Army's major source of reliable manpower was in the Western Soviet Union, and much of that was under German occupation in 1942.
This is not to say that the Red Army did not try to make use of the manpower that could be found in the Caucuses and Central Asia - it just didn't work out. Language barriers represented a formidable obstacle to integrating non-Russian speaking populations into the Red Army. The Red Army raised twenty-six rifle or mountain divisions from the Caucuses, Central Asia, and Baltic states, but almost none of these were deployable against the Germans. Though four Armenian rifle divisions saw combat, as well as the majority of Georgian units, those cases proved the exception rather than the rule. For instance, only three of fifteen Uzbek units saw combat and the Chechen-Ingush cavalry divison never came close to a battlefield. The loss of population in Western Russia, Belorussia, and the Ukraine therefore had an outsized impact on Soviet military potential as a whole. Moreover, there is a strong argument that that had the Germans, even in failing to meet the goals of their 1941-1942 campaigns, merely been able to hold onto the Soviet population centers captured in 1941-1942 that the Red Army may have been in deep trouble. That's because as early as January of 1943 a key component in the Red Army's ability to rejuvenate its strength would be its ability to move west and recapture land and population lost to the Germans. For evidence as to that we need look no further than the Voronezh Front's experiences early in 1943 as it pursued German forces withdrawing from Southern Russia as the German pocket at Stalingrad was slowly being reduced.
From January 13th to March 3rd 1943 the Voronezh Front's pursuit operations further beat up the Axis armies in Southern Russia but at a cost of 100,00 casualties (this included 33,331 irrecoverable losses) from the front's total initial strength of 350,000 men. To help ameliorate these losses the front received nearly 50,000 replacements during January and February. However, less than 10,000 of these replacements represented trained manpower released from the Stavka reserves. The largest single category of replacements comprised 20,902 men press-ganged into service from recaptured territory as the front moved west. The remainder consisted of front reserve units, previously sick or wounded men released from hospitals, liberated prisoners of war, penal troops (men released from the gulag and prisons) and the like. This meant that forty percent of the Voronezh Front's replacement manpower only came about because the front was able to move west. Nor was this situation unique. At this point in the war the Red Army was running short in the trained reserves needed to replenish the massive losses still being incurred while it also built up a strategic reserve and created new units.
The manpower problems facing the Red Army proved a constant throughout the Second World War. Even December 1944 revisions to the shtat of rifle divisions (when the Red Army was otherwise knocking on Germany's door) saw the number of rear-area personnel assigned to a rifle division cut in half compared to where it had been in June of 1941 (1,852 to 3,359 such personnel). At the same time the Red Army had spent 1944 making strenuous efforts to locate and press into immediate service (i.e. without training) men as old as 45 from the recaptured territories in the Western Soviet Union. By 1945 the Red Army was even taking Soviet citizens and POW's found on the march into Germany. These people, who had previously been rounded up by the Germans for service in the Third Reich's factories, were being sent to flesh out front-line ranks even though most were hardly in the physical condition needed to perform adequately in combat. Going back to early in 1942 we find entire rifle divisions being manned by far from inexhuastible sources of manpower. For instance, in April of 1942 the 112th Rifle Division was manned by Siberian Russians and penal troops.
So PoD becomes clear, in that you have the Anti-Nazi plotters kill Hitler and perhaps Himmler, leading to Goering taking over backed by the Army. Goering and much of the Army would be opposed to what became Citadel, and thus we have no historic Kursk. Probably sometime in July, Stalin will give into his desire to attack and order an offensive against the Germans, who have remained on the defensive. Based on what happened historically along the Mius and in Belarus from late 1943 into early 1944, and with the ATL benefit of not having exhausted themselves on the offensive, the Germans will likely stand firm, inflicting heavy casualties and surrendering territory only moderately, perhaps even minorly.
At that point, the USSR is shot as an offensive power and the Germans are increasingly too tied by the Anglo-Americans to take advantage of the situation. It strikes me as likely both sides will cut a deal in that context and abide by it.