Why did German military leaders expect to defeat the Red Army within a few months?

German military leaders, including Adolf Hitler and the heads of the Oberkommando des Heeres, expected to defeat the Red Army within a few months due to several key miscalculations and strategic assumptions:

• Superior Military Technique: The Germans believed their military forces, which constituted the largest and most powerful invasion force in history, would shatter the original Soviet armies through superior tactical execution and the speed of Blitzkrieg warfare.12
• Political Collapse: German leadership held the mistaken belief that the Soviet regime would collapse within three to six months of the invasion due to a lack of domestic support.1
• Underestimation of Reserves: German intelligence significantly underestimated the Soviet Union's capacity to mobilize fresh troops. While they expected the Soviets to produce roughly 50 additional divisions, the Soviet Union actually deployed more than 200 fresh divisions by mid-August.1
• Strategic Overconfidence: Hitler and his generals were convinced they could conquer the European portion of the Soviet Union west of a line from Arkhangelsk to Astrakhan by the end of October 1941.13