Montefiore, Simon Sebag. "Stalin Flees Moscow in 1941"
Divergence: 1941 CE
What if: As German troops closed on the city, Josif Stalin left Moscow in October 1941.
Summary: With Stalin's lead, Zhukov allows Moscow to fall to the Germans, and the Central Committee follows up by removing Stalin from office and having him executed. Molotov takes power and rules the Soviet Union into the 1980s, but history otherwise remains much the same.
Published: In What Might Have Been: Leading Historians on Twelve 'What Ifs' of History (ed. Andrew Roberts), q.v.