The abandonment of deep operations had a huge impact on Soviet military capability. Fully engaging in the Second World War (after the Winter War) the German invasion of the Soviet Union in June 1941, the Soviets struggled to relearn it. The surprise German invasion (Operation Barbarossa) subjected the Red Army to six months of disasters. The Red Army was shattered during the first two months. Thereafter it faced the task of surviving, then reviving and maturing into an instrument that could compete with the "Wehrmacht" and achieve victory.