German field fortifications were highly developed and were as effective as any others employed during the war. The specified designs of individual positions were well thought out, and were designed to protect against direct and indirect fire and from being overrun by tanks. They could accommodate troops and weapons, allowing them to take full advantage of their capabilities. However, individual positions, no matter how well designed, were ineffective unless fully integrated into a defensive system that coordinated the various elements of adjacent positions, obstacles, fire support, reserves and command and control. Avenues of approach and obstacles (including minefields) needed to be kept under constant observation to prevent surprise attacks. Camouflage and concealment from both ground and air observation were essential, including deception measures such as decoys and dummy positions. The overall layout and layering of the defences in depth was also essential to a successful defence. German troops were capable of achieving all of this, and often did so (with time, resources, weather and the tactical and operational situations permitting).
In most instances the Germans, at all levels, adhered to the basic precepts of selecting, locating and building field fortifications. For the most part they were well positioned, effectively covered their assigned sectors of observation and fire, provided mutual support to adjacent positions, made good use of their weapon’s capabilities, were well camouflaged (especially at ground level), and fitted well within the terrain and avenues of approach to their positions. In particular, the obstacles employed made good use of natural features to create more effective barriers, but there were many instances when the Germans failed to maintain observation and fire on these areas – more a result of a specific tactical situation or a lack of resources as opposed to the neglecting of key principles. Camouflage was sometimes deficient, especially overhead, a factor usually due to insufficient time and resources, coupled with the inherent difficulties of hiding from airborne observation.
While mud could severely hinder offensive operations, it also made life difficult for defenders dug into field fortifications.
The Germans demonstrated a great deal of flexibility, ingenuity and initiative in adapting their doctrinal defensive tactics and techniques to the varying terrain and weather conditions on different fronts. Field fortifications and obstacles were modified and new ones designed to exploit locally available materials (vital when considering how limited supplies were) as well as to attempt to counter new Allied assault tactics and heavier armour.
Regardless of the front on which the Germans defended, the most significant problem they faced was the lack of sufficient troops to provide adequate in-depth defence, and of armour and other motorised units for a mobile reserve allowing rapid and hard-hitting counter-attacks. No defence could resist a strong, well-coordinated, combined-arms attack supported by massive artillery and air resources. The defence line could be restored or partly restored if strong mobile reserves could conduct substantial counter-attacks, but the lack of air defence cover, or rather the air superiority of the Allies, prevented the timely commitment of mobile reserves even when they were available.
The well-built, multi-storey, interconnected buildings of European urban areas provided robust defensive positions. When destroyed, the rubble created countless hiding places for defenders and obstacles to the attackers.
The Allies developed extremely effective offensive tactics to deal with German defences. Allied basic doctrine was repeatedly modified and perfected as new weapons came available and lessons were learned. No two units, even within the same division, used the same assault tactics.
German combat troops in particular realised the fallacy of fixed, permanent defences, such as on the Westwall: these were used to strengthen the field fortifications, and not vice versa. Ultimately, the Germans were rarely able to develop complete mobile or elastic defences as specified by doctrine. What the defences did do was buy time at a strategic level. It should be noted that it took the Soviets from February 1943 (after the fall of Stalingrad) until 30 April 1945 (the fall of Berlin) – some 27 months – to bring the Germans to the point of defeat.
Little remains today of these field fortifications. In most areas new construction, agriculture and government polices have covered over the mostly temporary sites. Many of the semi-permanent concrete fortifications have been demolished too. However, in some remote areas of Germany, France, the former USSR and other countries, traces of trench lines and shallow, overgrown depressions can be found, marking the vanished frontiers of the Third Reich.