The biggest mistake of the Germans was that they did not expect to meet with such a rebuff of the Russians: true heroism, self-sacrifice, and hard work. The USSR proved its ability to mobilize its human resources, industry, and agriculture even under the terrible conditions of the first months of the war, when almost half the industrial and agricultural capacities were lost. The main achievement of
the USSR was evacuation and implementation of industrial plants, construction of new factories and enterprises, and development of new lands. The conversion of the economy to the war regime played a great role as well. The industry of the country was aimed at defense technology production, such as weapons, artillery, ammunition, tanks, fighters, and attack planes.