A Soviet surrender at Stalingrad allows Germany to claim the Caucasus and change history forever. There are several scenarios as to this move, and you can add your own or edit existing scenarios:
Black Cross, Stars and Stripes: After winning in Russia, Nazi Germany and the USA/Nationalist China face off in a Cold War.
Ashes to Ashes: After the defeat of the Soviet Union, the war becomes much bloodier, but the USA/Britain win the war.
Red Weeping: After the deafeat at Stalingrad, Beria takes over in a coup, and makes peace with Germany. A three way cold war erupts when Zhukov takes over in a coup d`etat and he, with many others, have a taste for revenge.