Glantz identified three turning points of the Soviet-German War. The Battle of Moscow  in the winter of 1941-1942 proved that Germany’s attempt to knock the Soviet Union out of the war in a single mighty blow had failed and that the struggle had become a war of attrition that the Soviets were rigged to win. The Battle of Stalingrad in the winter of 1942-1943 proved that Soviet tank armies (ie, combined arms mechanized armies) were capable of operational maneuvers of similar scale, tempo and depth as the German Panzer armies. Finally, the Battle of Kursk in the summer of 1943 broke the pattern of the winter being owned by the Soviets and the summer by the Germans; proved the operational superiority of the Red Army; and ensured that Germany would be conquered by Soviet arms.

Different scholars put different weights on these three turning points. Virtually all historians agree that the decision was clear after the third. The Germans themselves became convinced that they could no longer win after the second. Klaus Reinhardt argued forcefully in Moscow: The Turning Point that the first of these was decisive. Hitler’s strategy of conquest, he argued, could no longer succeed after the failure of Operation Barbarossa. There is merit to the early position. The Soviet Union had managed to evacuate a thousand factories and 20 million people beyond the Urals, so that the bulk of Soviet industry and war potential now lay beyond the operational reach of Germany’s eastern armies. This meant that the Soviet Union was now robust to operational solutions. The struggle had thus become a true war of attrition that Germany could not hope to win given the Soviet preponderance in armament and the American credit line.

While that is largely right, I’d like to temper that conclusion. It is true that, after the great evacuations, the bulk of Soviet war potential lay beyond the operational reach of Germany’s eastern armies. I will argue however that there was still the possibility of an operational breakthrough that had the potential to even the odds, or perhaps even reverse the odds.

Given the primacy of mechanized armies, oil was absolutely critical to the war effort. Baku on the Caspian Sea supplied 90 percent of Soviet oil. The capture of Baku would not only solve the German oil problem—a binding constraint—it would also deny this stupendous resource to the Red Army. The US was supplying the Soviet Union through three routes: the northern route through Archangel, the southern Persian Gulf-Caspian Sea route, and the eastern route through Vladivostok. Control of the Caspian Sea would not have cut-off the Soviet Union entirely from US oil supply. But it would have severely hampered it because the northern and eastern routes had limited carrying capacity. Archangel was only ice-free for a part of the year and there was a single, six thousand kilometer rail link between Moscow and Vladivostok.

Capturing Baku and cutting off the southern route could thus have had a decisive effect on the odds. This was the goal of Operation Blau. The operational targets were the two ports on the Volga, Stalingrad and Astrakhan. (The location of Stalingrad is marked by a swastika in the map below.) If the eastern armies could extend their control to the Volga from Stalingrad to Astrakhan, that would sever Soviet access to Baku. The Soviet armies trapped to the south could then be reduced in detail ensuring German control over the prize.

The objective was within the operational depth of the eastern armies. The German offensive did succeed in reaching the Volga; in the process destroying Soviet armies on the Don. The war hung in the balance as the Soviets mobilized their forces for a major counteroffensive.

Many accounts of the battle, such as the one on Wikipedia, focus attention to the battle for the city. While close-quarter urban combat was brutal and of great human interest, the battle was decided far away from the city. The Soviets launched pincer maneuvers to cut off the Sixth Army from its western supply lines and simultaneously attacked the German armies located west of the Don.

My argument is not so much that the eastern armies could have won the Battle of Stalingrad. Given the forces arrayed against them, that’s a tenuous claim. My argument is rather that, having reached the Volga, the Germans came close to severing the communication lines between Moscow and Baku. Had they managed to pull that off, the odds of the war would surely have evened out if not reversed outright. So, contrary to Reinhardt and my earlier claims, an operational solution of strategic significance was still on the cards in 1942. And it was only with the destruction of the Sixth Army that such operational solutions could be ruled out and one could therefore be certain of Allied victory against National Socialist Germany.