After the acceptance of these recommendations, the Commandant ordered classes discontinued at the Marine Corps Schools and a concerted effort applied to the preparation of a new amphibious manual. Both the Army and Navy had treated some of the procedures in existing manuals, but it remained for the Marine Corps in 1934 to put out the first complete work of the sort. Known as the Tentative Manual on Landing Operations, it became either directly or indirectly the guide for exercises and maneuvers of the Navy and Marine Corps down to World War II.
Most of its suggested procedures were endorsed with revisions in the Navy’s Fleet Training Publication 167, published in 1938. This work in its turn became the model three years later for the Army’s first basic field manual for landing operations.[77]
[77] FMFPac, History, 6–9.
Training exercises were held every year, usually at Culebra or Vieques in the Caribbean and San Clemente Island off San Diego. At the suggestion of the Fleet Marine Force, the Navy purchased Bloodsworth Island in Chesapeake Bay as the first amphibious gunfire range used for that purpose alone.
Schools were set up to train Army and Navy as well as Marine officers as specialists in fire control parties. Air support was closely integrated with naval gunfire, shore artillery, and troop movements. Technology came to the aid of tactics when the Fleet Marine Force encouraged and supervised the designing of strange new amphibious craft and vehicles. Concepts were actually based in several instances on landing craft not yet developed and the confidence of the Marine Corps in American inventiveness proved to be justified.
Thus the Nation entered World War II with a system of offensive tactics which opened Europe, Africa, and the islands of the Pacific to American invasion without incurring a single major defeat. Not only was the United States ahead of the enemy in the development of amphibious operations but the Axis Powers never found the key to an adequate defense. In an often quoted summary, the British military critic and historian, Major General J. F. C. Fuller, has asserted that these techniques were “in all probability ... the most far-reaching tactical innovation of the war.”[78]
[78] MajGen J. F. C. Fuller, The Second World War (London, 1948), 207.
During the next few years the Marine Corps was twice officially given the major responsibility for American amphibious tactics. The National Security Act of 1947 made it the function of the Corps “to provide fleet marine forces of combined arms, together with supporting air components, for service with the fleet in the seizure and defense of advanced naval bases and for the conduct of such land operations as may be essential to the prosecution of a naval campaign.”[79]
[79] 61 U. S. Stat. at L. (1947), 495.
At the so-called Key West Conference the following spring (March 11–14, 1948), the Secretary of Defense and Joint Chiefs of Staff restated the Marine Corps’ mission to include that of developing “in coordination with the Army, the Navy, and the Air Force, the tactics, technique, and equipment employed by landing forces in amphibious operations. The Marine Corps shall have primary interest in the development of those landing force tactics, techniques, and equipment which are of common interest to the Army and the Marine Corps.”[80]