German Command and Tactics in the West, 1944
It may be that the most serious weakness of the German defense in the west was not the shortage of men and materiel but the lack of a unified command. While Rundstedt was charged with the entire responsibility for the defense of France and the Low Countries, his powers were far from commensurate with that responsibility. He had, in the first place, no command over air and naval units. The four air corps that comprised the fighter and bomber aircraft stationed in the west were under command of the Third Air Force (Generalfeldmarschall Hugo Sperrle), which in turn was directly subordinate to OKL. Similarly Navy Group West, which under Admiral Theodor Krancke commanded the destroyers, torpedo boats, and smaller naval vessels based in the ports within Rundstedt's jurisdiction, was responsible directly to OKM. Rundstedt could issue no orders to either Sperrle or Krancke; he could only request their co-operation.
Air and naval forces were too small to have decisive effect on the battle. From Rundstedt's point of view the more important limitation of his power was the fragmentation of the command over the ground forces. Some of this fragmentation was normal and universal in the German military establishment. The Third Air Force had, for instance, besides command of the flying units, administrative control over parachute troops and the antiaircraft units that were under the III Flak Corps. Navy Group West controlled through regional commanders not only ships and shore installations but most of the coastal artillery, although command of the latter was mixed. The Navy had complete jurisdiction before operations on land had begun. Afterward, firing on sea targets remained a naval responsibility, but at the moment of enemy landing, in most cases, command of the batteries in the beachhead area was to pass to the Army. Virtually the whole burden of tying in the important naval batteries to the coastal defense was thus shifted to the initiative of local commanders.
A similar division of command affected the employment of the security troops which as instruments of the occupation were normally under the two military governors (Militaerbefehlshaber), France and Northern France (including Belgium). The military governors were directly subordinated to OKH, but for purposes of repelling invasion their security troops might be tactically under OB WEST. In preparation against invasion, the Commander in Chief West could only direct that the military governors co-operate with the army groups in matters affecting the latter's authority and undertake to settle any differences that might arise between them. Even this control was limited. Employment of security troops could only be ordered by the Commander in Chief West "in matters outside the scope of security."
During 1944 OB WEST's authority was abridged in special ways. In November 1943, it will be recalled, Field Marshal Rommel had taken command of the Army Group for Special Employment, which was charged at first with inspection of the western defenses and the preparation of plans for counterattack against the main Allied landings wherever these might take place. Ultimately the Rommel headquarters was to conduct the main battle against the invading forces. About the middle of December, Rommel, having completed the first of his tasks, the inspection of the coastal defenses of Denmark, arrived in France and began a survey of the Fifteenth Army sector. Both he and Rundstedt recognized at once that it was neither logical nor practical for the Special Army Group to remain outside the theater chain of command. Its independence could only be a source of friction and inefficiency. On 30 December Rundstedt recommended that it be subordinated to OB WEST as Army Group B with command of the Seventh and Fifteenth Armies and of the German Armed Forces of the Netherlands. Whether the initial suggestion for this change came first from Rommel or from Rundstedt, it was clearly in the beginning agreeable to both. Since the main Allied invasion was likely to strike somewhere along the Channel coast, it made sense to put Rommel in immediate command there in order to familiarize him with his task and allow him to take such steps as he found necessary to strengthen the defense. Hitler approved but warned OB WEST that the Rommel headquarters was still to be considered available for commitment elsewhere. Rundstedt accepted the condition, and the reconstitution of Army Group B was ordered to take effect on 15 January. Rommel's subordination to OKW was at this time canceled.
His position, however, remained anomalous: whereas he had less than full command over the armies attached to him, he enjoyed an influence over the whole defense of the west which was in some measure commensurate with Rundstedt's. His orders provided that he was to be solely responsible for the conduct of operations (Kampffuehrung), but that in matters not directly affecting this tactical command OB WEST would continue to deal directly with the armies. Thus on questions of defense, training, organization and equipment, supply, artillery matters, communications, and engineer problems, the command channel might bypass the new army group.  Rommel continued to be the coastal inspector for the whole of the west, and although his reports henceforth were forwarded through OB WEST his ability to influence coastal defense policies and practices did much to blur his subordination to Rundstedt. Moreover the binding of the Rommel staff to a geographical sector was only tentative; the headquarters was thought of still as a reserve command and as such the recommendations of its commander carried special if informal weight. Finally, and most importantly, Rommel in common with all German field marshals enjoyed at all times the right of appeal directly to Hitler. That privilege was especially important for the west because of the personalities involved. The evidence indicates that Rommel had an energy and strength of conviction that often enabled him to secure Hitler's backing, whereas Rundstedt, who was disposed whenever possible to compromise and allow arguments to go by default, seems to have relaxed command prerogatives that undoubtedly remained formally his. It is possible, of course, that he too came under Rommel's influence and failed to press acceptance of his own ideas because he was content to allow Rommel to assume the main burden of responsibility. In any case the clear fact is that after January 1944 Rommel was the dominant personality in the west with an influence disproportionate to his formal command authority.
Rommel's position, however, was not unchallenged. In November 1943 Rundstedt, thinking in terms of a large-scale counterattack against the main Allied landings, created a special staff to control armored units in that attack. The staff, designated Panzer Group West, was headed by General der Panzertruppen Leo Freiherr Geyr von Schweppenburg, and was directed to take over at once the formation and training of all armored units in the west and to advise the Commander in Chief West in the employment of armor. Geyr was ordered to co-operate with and respect the wishes of army group commanders. Actually, however, Geyr's ideas on the proper employment of armor were so completely at variance with Rommel's that co-operation was impossible.
In March 1944, at a meeting of the senior commanders in the west with Hitler, Rommel asked for an extension of his own authority that to all intents would have eliminated Geyr and Rundstedt as well from effective command of the defense forces. Specifically he requested that all armored and motorized units and all GHQ artillery in the west be put directly under his command and that he also be given some control over the First and Nineteenth armies. The latter two armies, defending the Atlantic and Mediterranean coasts of France respectively, were at this time still subordinated immediately to OB WEST. In one sense, Rommel's request logically arose from his mission. Assigned responsibility for countering the major Allied invasion attempt, he required control over all the forces that might be used in the defense. It was plausible furthermore that such control should be turned over to him before the battle so that he could properly prepare and dispose the troops to fight the kind of battle he would order. Making a strong bid to unify defense policies, he asked that the Humpty-Dumpty command in the west be put together again under him. Although the method of repair naturally did not please Rundstedt, his objections were unheeded at the March meeting and Hitler approved the expansion of Rommel's command. Only after a study by the operations staff of OKW had supported Rundstedt's later written protest did Hitler reverse himself. Even then the reversal was not complete. Three panzer divisions (the 2d, 21st, and 116th) were assigned to Rommel as Army Group B reserves, over which he was to have full tactical control while Geyr remained responsible for their training and organization. The patchwork solution solved nothing.
At the same time four other panzer-type divisions in OB WEST's sector (the 1st SS Panzer, 12th SS Panzer, 17th SS Panzer Grenadier, and Panzer Lehr) were set aside as a central mobile reserve under the direct command of OKW. The two decisions smacked of a compromise tending to preserve something of both Rommel's and Rundstedt's tactical ideas. The main effect, however, was to deprive the Commander in Chief West of the means to influence the battle directly without transferring those means to Rommel. Thus, even such inclusive authority as was possible in the German military establishment was scrupulously withheld from both high commanders in the west.
The final command change before the invasion was made in May when Rundstedt ordered the formation of a second army group headquarters to take command of the First and Nineteenth Armies. Army Group G, formed under Generaloberst Johannes Blaskowitz, took over, besides the two armies, the remaining three panzer divisions in France (the 9th, 11th, and 2d SS). The reorganization provided a counterbalance for Rommel and somewhat simplified the command channels. It probably also expressed final recognition of the impracticability of the reserve high command concept.
With the establishment of Blaskowitz's headquarters, Rundstedt undertook to define his own position. He outlined for himself what amounted to an over-all ground command in his theater, subject to the restrictions already discussed. He announced his intention of granting his army group commanders the maximum freedom of action in their own sectors. He would intervene only when he fundamentally disagreed with their policies or when decisions had to be made affecting the theater as a whole. He promised to confine his directives to passing on Hitler's orders and to specifying policies that ought to be uniformly carried out by all commands.
In fact, during the critical preparatory months of 1944, general directives were few either from Rundstedt or Hitler. Hitler, far away at his headquarters in East Prussia, was so preoccupied with the Russian war that he did not even visit the west until after the invasion. Furthermore he seems not to have had any clear and consistent view of tactics himself, and his interventions in the western scene resulted more often in decisions of detail than in definitions of policy. The failure of Hitler to provide consistent guidance together with the vague demarcation of authority between Rommel and Rundstedt left the west with a vacillating leadership. Defense preparations in 1944 were increasingly scarred by compromise as the Commander in Chief West and the commander of Army Group B made detailed decisions in accordance with divergent aims.
The perspective from which Rommel viewed his task derived in part from his experience with desert warfare in North Africa and in part from the circumstances of his new assignment. It is important to bear in mind that Rommel came to the west only at the point when the battle was about to be fought there, and that he was assigned responsibility specifically for the conduct of that battle. He had not endured the long waiting period with its periodic alarms. He had not spent months making plans, calculating actual but shifting deficiencies against ideal needs, outlining defense systems and struggling to find the means to carry them out. The theoretical approach to tactics-the drafting of the abstractly best plan first, the search for resources second-was ruled out by the nature of his mission as well as by the limited time at his disposal. He was appointed coastal inspector and told to assess defensive capacities and make his plans accordingly. Whatever he chose to do had to be completed in three or four months. He was bound therefore to start by examining his limitations.
The experience in North Africa had convinced Rommel of the folly of trying to use massed armor as long as the enemy enjoyed air superiority. In Africa Rommel commanded some of the best trained and equipped troops that Germany produced. In France he was to command an army that was already crippled in part by inadequate training, inferior human material, and lack of mobility. Furthermore, there was still less hope in 1944 than in 1942 that the Luftwaffe could challenge the supremacy of the Allies in the air. To Rommel that meant that mobile operations were impossible in fact however desirable they might be in theory. If the German Army could not hope to maneuver on anything like terms of equality with the Allies, its only chance for a defensive success was to fight from the strongest possible natural positions. The pillboxes, entrenchments, wire, and mines of the Atlantic Wall and the waters of the Channel, in short, seemed to Rommel to offer not only the best but the only means to offset Allied superiority in mass and mobility.
Rommel therefore was led to place an exclusive dependence on fortifications that Rundstedt never advocated and that even Hitler had not contemplated in his directive of November. The battle for the west, Rommel believed, would be decided at the water's edge, and the decision would come literally within the first forty-eight hours of the Allied landings. In accord with that diagnosis, his first aim was to create a defensive belt around the entire coast with special concentration on the Fifteenth Army sector) extending five or six kilometers inland. Within this belt all infantry, artillery, headquarters staffs, and reserves up to division level were to be located in a series of resistance nests. Between the resistance nests mines and obstacles were to be laid so thickly as to prevent enemy penetration. Because of limited time, labor, and materials, Rommel concentrated on many simple, field-type defenses rather than on a few complex fortifications. He stressed in particular the laying of mines. He introduced further, a defense device new to the Atlantic Wall: underwater obstacles designed to wreck landing craft. In Normandy, hedgehogs and tetrahedra located inland as tank obstacles were moved to the beaches suitable for enemy landings. Belgian Gates and stakes slanting seaward supplemented them. The intention was to cover every possible landing beach between high- and low-water marks with obstacles staggered to leave no free channel for even a flat-bottomed boat to reach shore. Obstacles as far as possible were to be mined. As it was considered most likely that the Allies would land at flood tide to reduce the amount of open beach to be crossed under fire, laying of the obstacles began at the high-water line and was extended in belts seaward as materials and labor became available.
To complete his hedgehog fortress, Rommel undertook to stake all fields suitable for glider landings behind the coastal zone. The stakes were to be placed close enough together so that gliders could not come down between them. They, too, were to be mined. The German estimate was that Allied airborne troops would be used in diversionary and subsidiary operations, for which Brittany and Normandy were considered the most likely target areas. Rommel therefore concentrated the erection of antiairlanding obstacles in these areas.
The general scheme of obstacle defense of the Continent was further to be extended by mine fields in the Channel. Sixteen fields, each about five miles long, were put down in the Channel between Boulogne and Cherbourg from August 1943 to January 1944. These were to be kept renewed as far as possible, but it was not believed that they would have much effect on Allied shipping. They were therefore to be supplemented by hasty mine fields laid down by all available vessels immediately before the invasion was expected. These fields would be planted without keeping open any marked lanes for German vessels. From Zeebrugge to Granville thirty-six mine fields were planned. It was also planned, when invasion seemed imminent, to sow mines from the air in British harbors. Finally along the French coast shallow-water mines were to be laid and a special seventy-kilogram concrete mine was developed for the purpose.