Soviet forces suffered heavy damage in the field as a result of poor levels of preparedness , which was primarily caused by a reluctant , half-hearted and ultimately belated decision by the Soviet Government and High Command to mobilize the army . Equally important was a general tactical superiority of the German army , which was conducting the kind of warfare that it had been combat-testing and fine-tuning for two years . The hasty pre-war growth and over-promotion of the Red Army cadres as well as the removal of experienced officers caused by the Purges offset the balance even more favourably for the Germans . Finally , the sheer numeric superiority of the Axis can not be underestimated
Purges
Great Purge
Soviet Armed Forces