Complex sentence: According to Soviet historiography, this policy was adopted by the Bolsheviks with the goal of keeping towns and the Red Army supplied with weapons and food because the ongoing war had disrupted normal economic mechanisms and relations.
Split into simpler sentences: According to Soviet historiography, this policy was adopted by the Bolsheviks with the goal of keeping towns and the Red Army stocked with weapons and with food. The system had to be used because the ongoing war disrupted normal economic mechanisms and relations.