With the fall of France in 1940, the Army began to give serious thought as to how any expeditionary force would be deployed to Europe in the event of the US entry into World War II. Obviously, with virtually all continental ports in Nazi hands, amphibious operations would be required. The Army hadn’t engaged in large scale amphibious operations since the Spanish American War, and conventional thinking at the time was that amphibious operations were almost doomed to failure (thinking largely influenced by the British experience at Gallipoli in World War I).
The Marines had devoted considerable thought to amphibious warfare during the interwar years, of course, but even so, their advances were more doctrinal than practical. Few of the assets needed to make assault landings existed in 1940. Further, the Marines faced a distinctly different challenge from the one that the Army foresaw.
The Marines in the interwar years, like the Navy, looked upon an expansionist Japan as a likely threat to peace. In planning any war against Japan, advanced naval bases much farther west than San Diego or even Hawaii would be needed to support the US possession of the Philippines and to take the fight to Japan itself. Under the provisions of naval disarmament treaties in the 1920s, the US had foregone fortifying any positions in the Western Pacific. The Japanese were not so constrained. So the Marines lighted upon the mission of seizing and defending advanced naval bases as a raison de etre. The first iterations of this focus did not anticipate attacking into the teeth of defended islands. Rather, undefended islands would be occupied, and Marine Defense Battalions with strong coast and anti-aircraft artillery would hold the position from any counterattack.
This paradigm didn’t take into account the pivotal role that airpower would come play in modern warfare. As war loomed closer, however, it became clear that not only would the Marines need to seize bases for the Navy, they would also need to deny bases to the Japanese, lest land based airpower dominate the seas upon which both the Navy and commerce depended on. Accordingly, the Marines and the Navy began to develop the doctrine and organizations needed to attack hostile shores. Development of the practical equipment for such landings lagged badly behind, mostly due to the extremely austere budgets of the day, but what little funding could be found was invested wisely. The early efforts to develop specialized assault shipping and landing craft would lead directly to the development of landing craft such as the Higgins boat, the LCVP, the LCM and the LCT.
The Maries began to consider assault landings of regimental or even divisional size. For an organization that had spent the majority of its history working as small shipboard detachments, that was heady stuff. A reinforced regiment or division of Marines would travel hundreds, even thousands of miles to an objective aboard large ships, transfer to small landing craft, attack an island, seize it, and allow follow on naval elements to improve facilities to build airfields and naval facilities.
But the Army had a different problem. While the Marines were likely to face a series of short, sharp fights for relatively small, discrete objectives, the Army needed to land forces in large numbers just to come to grips with the enemy. Any amphibious operation the Army was likely to partake in was merely the means of opening a theater of war, not an end in itself.
The first formal efforts to build an amphibious capability in the Army began in 1940, with the establishment to two Amphibious Corps, one on the east coast, and one of the west. Each corps consisted of one Army division and one Marine Division. Each corps would fall under the overall control of the Navy. It is a little ironic, given the Army’s focus on Europe that the initial objectives of these corps were defense of objectives in the Western Hemisphere.
Exercises and planning soon showed the shortcomings of these organizations, and they were eventually disbanded, with the Marines again focusing on the Pacific. The Army continued to train divisions for amphibious operations, first at Cape Cod, and later in Florida.
With the entry of America into the war, the British and the Americans began planning to come to grips with the German Army. Early plans included a cross-Channel assault as early as 1942. The British saw this as a desperation move, to be implemented only if the Russians seemed on the verge of collapse, or less likely, if the Germans seemed about to collapse. The US Army, however, thought the commitment was firm, and accordingly placed great emphasis on preparing units for the operation. The goal was to have eight to twelve divisions trained for amphibious assault.
The US Navy balked. With the terrible losses at Pearl Harbor, and the overriding need to provide escorts for convoys in the Atlantic, the Navy didn’t have the resources to provide landing craft and crews for a major assault. It wouldn’t be until late 1942 or even 1943 that they would be able to lift more than two divisions.
The Army, somewhat naively, thought of an attack across the English Channel as little more than a river crossing o a major scale. If they Navy wouldn’t lift them, they’d lift themselves. Almost overnight, the Army organized the 1st Engineer Amphibious Brigade. The 1st EAB would provide LCVP and LCM landing craft sufficient to lift a reinforced infantry division, the boat crews, and the maintenance to support them. Almost as important, the brigade had shore parties to organize the beachhead, establish dumps and move supplies from the waterline to those dumps, and evacuate casualties from the beach.
If the idea of crossing the English Channel in small boats was naïve, the Army did grasp the critical concept that ensuring a smooth flow of supply and reinforcement over the beaches would require a special organization with special skills. Getting ashore was hard. Staying ashore was harder.
The British were appalled. Having been defeated by the Germans in every major engagement so far in the war, and having been kicked out of France, they were in no rush to attack the main strength of the Wehrmacht until it had been bled white, through air attack, naval blockade, peripheral operations, and most importantly, by the Red Army. The flatly refused to consider a cross Channel attack in 1942. Secondly, the US Navy was appalled. First, there was the usual matter of interservice rivalry and prestige. The though of the Army making landings on their own was just too much. Secondly, and more importantly, the Navy grasped that any cross Channel attack would have to be mounted from far larger ships than light landing craft. The strength of the Army came from its high degree of mechanization, and to move those vehicles would call for more than just LCVP and LCM.
With no prospect of an invasion of Europe for 1942, the Allies still needed to take some offensive action somewhere. The decision was made to land in French North Africa, and move to reinforce those British forces fighting the Germans and Italians in Egypt and Libya, and to eventually seize Tunisia as a base for further Mediterranean operations.
Any such landing was clearly far beyond the capacity of the EAB to lift. The landing would have to be made from Navy transports. The boat sections of the EAB were disbanded, and the troops converted to longshoremen and basic labor troops to move supplies from the beaches to inland dumps.
But the EAB wasn’t done just yet…