Anniversary parade for V-E Day in Berlin in 1946; checkpoint on the West's side of Berlin in 1949

Post-WWII, Germany was divided into four zones controlled by France, the USA, England, and Russia. This division led to the creation of East and West Germany as separate states. Russia was open to a unified Germany only if it became a communist puppet state.

What were the four zones of occupation in Germany after its division?

Which countries controlled the zones of occupation in Germany?

What was the major unwritten division that affected Germany?

What did Russia want regarding the unification of Germany?

What condition did Russia have for a unified Germany?