The Wehrmacht forces for the Ardennes Offensive were the product of a German recruitment effort targeting German males between the ages of 16 and 60, to replace troops lost during the past five months of fighting the Western Allies on the Western Front. Although the Wehrmacht (German Armed Forces) was keeping the Allied forces contained along the Siegfried Line, the campaign had cost the Wehrmacht nearly 750,000 casualties, mostly irreplaceable. However, the rapid advance of the Allied armies in August and September after Operation Overlord had created a supply problem for the Allies. By October, the progress of the Western Allies' three army groups had slowed considerably, allowing the Germans to partly rebuild their strength and prepare for the defense of Germany itself. Adolf Hitler dec