 In 1941 the rapid progress of the initial German air and land attacks into the Soviet Union made Red Army logistical support difficult because many depots (and most of the USSR's industrial manufacturing base) lay in the country's invaded western areas, obliging their re-establishment east of the Ural Mountains.Until then the Red Army was often required to improvise or go without weapons, vehicles, and other equipment.The 1941 decision to physically move their manufacturing capacity east of the Ural mountains kept the main Soviet support system out of German reach.