On 29 November, after a review of the situation on the Eastern Front with the head of the General Staff's Operations Section, Halder authorized the preparation of orders for a general winter defense. [119] Drafted over the next week, this order became Fuhrer Directive 39, which Hitler signed on 8 December.

Taken at face value, Fuhrer Directive 39 resembled the shrewd 1917 plan to withdraw to the Hindenburg Line that had inaugurated the German Elastic Defense. Although framed in strategic terms, Fuhrer Directive 39 (and the Army High Command's implementing instructions that accompanied it) generally followed the traditional principles of the elastic defense in depth. Brauchitsch, the German Army's commander in chief, was directed to designate a winter defensive line. At his discretion, this line could be located to the rear of current German positions, although rearward fortifications were to be prepared prior to any tactical withdrawals. (Significantly, in light of subsequent events, this showed an initial willingness even on the part of Hitler to relinquish terrain that did not contribute materially to German goals.)

The defensive line itself was to be held with minimum forces, allowing combat units--and especially panzer and motorized divisions--to be refitted in reserve positions farther to the rear. These rehabilitation and reserve areas were to be located fairly close to the front lines to facilitate rapid reinforcement of threatened sectors. Defensive positions were to be sited for optimum defensive effectiveness and comfortable troop quartering. Moreover, to provide additional defensive depth, the order emphasized the construction of rearward defensive positions, using whatever manpower could be scraped together. [120]

Fuhrer Directive 39 was historically significant because it implicitly conceded that the German armies had failed to achieve Barbarossa's strategic objectives. The Soviet Union, though suffering enormous losses in the summer and autumn battles, had not been conquered in a "single, lightning campaign." Moscow, belatedly named the climactic operational objective, remained beyond the German reach. Fuhrer Directive 39 blamed these failures on the premature winter weather and resultant supply difficulties. More crucial, however, was the vastly depleted German combat power. The offensive exertions of the previous five months had so sapped German strength that German units had become unfit for combat of any sort, whether offensive or defensive.

In a situation analogous to that encountered by the Allies in 1918 following the Ludendorff offensives, Soviet counterattacks revealed that German units were scarcely able to hold the ground they had recently won. Red Army soldiers, testing German lines outside of Moscow with local counterattacks, discovered to their surprise that German resistance was spotty. Exploiting tactical successes, these Soviet counterblows gradually swelled in scope and intensity. By the beginning of December, the Soviet High Command had recognized the frailty of the German position and threw all available forces into a general counteroffensive. Beginning on 6 December, this counterstroke tore open the German front and created the greatest strategic crisis yet faced by the Germans in the war.

Thus it was that Fuhrer Directive 39, though significant in reflecting German defensive intentions, failed to have any real effect on the conduct of winter operations by the German Army. Whereas the German winter defensive order assumed a smooth, deliberate transition to positional defense, Soviet counterattacks were already forcing battle-weary German units into headlong retreat. Belatedly issued on 8 December, the German defensive order had already been made obsolete by events. As in the defensive battles during Barbarossa's drive eastward, German winter defensive tactics were to be dictated more by local conditions than by doctrinal prescription.