 On the eve of the Soviet Vistula–Oder Offensive, in January 1945, the Red Army had an impressive force of 1,670,000 soldiers, 28,360 artillery guns and heavy mortars, over a thousand Katyusha rocket launchers, 3,300 armored fighting vehicles and nearly 3,000 aircraft.Against this, two out of five army groups positioned on the Eastern Front, Army Group Center and Army Group A, lay in the path of the Soviet offensive; together, they could count on roughly 980,000 personnel, 1,800 armored fighting vehicles, and nearly 900 combat aircraft.During December 1944 the Wehrmacht had concentrated the bulk of its mechanized forces and logistical support on the Western Front, reducing its ability to defend Germany's eastern border from the Soviet Union.