The Soviet Union came around as a result of the Russian Revolution ending Tsarism in Russia. This was compounded by the rise in general power of the Proletariat and the ideology of Marxism which lead into Communism. Soviet Constructivism was born under these conditions, with messages of ending Bourgeoise reign and putting power into the hands of the Proletariat.
During this period of social reconfiguration, Russia was not very rich. This led to a shortage of unused film stock, meaning Russian directors couldn’t film movies at will. However, what they did have was was stock that was already used. These conditions are what led to the major developments in editing that was representative of the Constructivist movement. They couldn’t focus on things like cinematography since they could only use films others had made. Directors like Kuleshov and Eisenstien used this chance to develop techniques related to editing, such as the Gerasimov Effect or the 5 methods of montage.