Many Tzars tried but failed to modernize Russia throughout its history. Then the Bolsheviks took power in 1917 and were able to achieve significant progress in the industrialization and militarization of the country. Even to the point that Hitler said, “Had I known they had as many tanks as that, I’d have thought twice before invading.” link to quote
It's been argued that, during the end of 1941, Russia's unpaved roads and "general mud" slowed the German advance. Early in the war the Russians lacked schooling in mobile warfare but as they learned it from the Germans the Industrialization that began under the Bolsheviks gave them the material they needed to win the war.
How much of the success of the Soviet forces in WWII can be attributed to the modernization efforts enacted by the Soviet/Bolshevik leadership? How different was the country's indutrialization trajectory under the Soviets than under the Tsars?