 Complete the following phrase:  Axis air superiority early in the conflict limited the ability of the Soviets to mount such operations, whilst later in the conflict ongoing shortages of materiel, including silk for parachutes, was also a problem. Nonetheless, the Soviets maintained their doctrinal belief in the effectiveness of airborne forces, as part of their concept of deep battle, throughout the war. The largest drop during the war was corp-sized the 