Military operations during 1940, in the European theater of war, afforded a striking succession of examples of the paralyzing effectiveness of modern mechanized attack, in which air power and tanks, in co-operation with well- trained ground troops, conclusively demonstrated the fallacies of the “total defense” school of strategy. During the battles in Flanders and France, as in 1918, the tactics of infiltration and exploitation were vindicated. Four neutral countries were overrun and used as mere avenues to outflank the Maginot defenses of France, and to gain a forward line extending from Norway to Brest for the attack on England. In all of these operations speed and precision characterized the onslaught of the German forces, while vacillation and disorganization marked the efforts of their opponents. The so-called Sitzkrieg of the opening months was transformed into a war of movement, unparalleled in violence, which rapidly attained its continental objectives ending with the complete collapse of France.
While these events were occurring, however, control of the sea remained in the hands of the British, and constituted, again, the greatest single obstacle to the successful accomplishment of German plans. Not only did it make possible the brilliant, in fact almost miraculous, evacuation of Dunkirk, and the reinforcement of distant armies, but it ensured, as well, a steady flow of supplies and war materials essential to fill the gaps in the sadly inadequate British war machine. Under cover of its protection there began the acquisition and distribution, by sea-borne transportation, of raw materials and of finished goods. The resources of the Western Hemisphere were tapped, and to the products of British industry were added substantial increments manufactured in security beyond the reach of the military and air forces of the Axis.
Sea power, in addition, successfully denied the projected invasion of England from the French ports, and clamped its “strangle hold” on Italian plans for an Egyptian offensive from Libya. The extent to which the action at Taranto contributed to the failure of the Italian offensive against Greece may still be open to conjecture, but certainly the newly established British bases on the Islands of Corfu and Crete menace the flank of any projected offensive through Turkey and Syria against Palestine and Iraq, even should the Axis partners ultimately succeed in joining hands on the Turkish border. These bases, furthermore, threaten Italian communications with the Dodecanese Islands, the reduction of which would greatly facilitate the rapid reinforcement of Turkey by British forces based in the Mediterranean area.
Against these accomplishments of sea power, air power, singlehanded and alone, to date can offer no comparable decisive results. It has inflicted, beyond doubt, serious damage to many important military objectives, and, in addition, has devastated large areas in various centers of population, but it has not yet been able to do more than harass and interrupt communications and transportation. The evidence at hand does not indicate that successful air raids on a decisive scale can be carried out during daylight in the face of determined resistance by fighter aircraft and anti-aircraft gunfire. Night bombardment, however, appears to hold an advantage over ground and air defense, but even so has no decisive achievements to its credit as yet. The most telling use of air power has been its employment in close co-operation with ground troops, but success in that field was in a large part due to air superiority established because of the weakness of the opposing air force rather than by combat. At Dunkirk, for example, the British were apparently able to establish a temporary air superiority. In Poland, Norway, Holland, and Belgium, the German Luftwaffe had such a tremendous advantage that the havoc created cannot be cited as applicable to a contest on even terms. The French air force, too, was never able to fight on even terms, and, in addition, suffered from faulty organization, which could not be corrected in time. As the French armies collapsed, it became impossible for air units to maintain the necessary facilities for supply and repair, and although gallantry was abundant, the pilot personnel was eventually engulfed in the general catastrophe. The German air successes up to the time of the French collapse, consequently, were consolidated by the fast moving ground forces, and the decision was therefore confirmed by the ground action rather than the air action, though it must be admitted that the German teamwork was excellent, and that the air contribution was important.
These conclusions are borne out by the results in the next phase, the so-called “Battle of Britain.” Here air power met on more nearly equal terms, both as to quality of machines and of personnel. Yet the British, although outnumbered, took a heavy toll of the invaders in all daylight actions. By night, both sides appeared to be able to press home telling raids, but so far, at least, without decisive results.
One of the new air techniques has been the German use of reconnaissance planes to spot convoys and to direct surface and subsurface attacks by radio. This presupposes a concentration of submarines and raiders in the offshore area, and, if successfully continued, might enable a decisive toll to be taken of shipping. But here again, the part of air power is contributory rather than decisive, and an adequate destroyer screen should and probably would afford sufficient protection, even though fighter aircraft are unable to deal with the reconnaissance planes because of the distances involved, and the lack of air bases in Southern Ireland. At any rate, it is a question of devising new methods of protecting convoys—such as close-in patrols by aircraft, or additional destroyers and small craft, for submarine operations in this war have been extended, by conquest of bases, too widely for actions of the Zeebrugge type to be effective.
In general then, the conclusion may be drawn that sea power retains its ancient promise as a decisive weapon, both because it can afford protection to the transportation of reinforcements of material and of personnel, and because it can deny such commerce to hostile powers. Sea power, however, requires its own adequate air protection, and only to the extent that this can be provided will it retain the ability to apply the strangle hold of blockade effectively. In the narrow seas adequate air protection must necessarily include shore- based aircraft in support of carrier-based formations, because hostile shore-based aircraft can otherwise be concentrated in numbers sufficient to assure air superiority. It is generally true that the range of shore- based aircraft exceeds that of carrier types at present, and that technical developments can be expected to maintain the gap in performance characteristics as time goes on, thus extending the definition of the term “narrow seas” to limits within which shore-based aircraft can operate effectively. It seems probable that this radius will soon become at least 1,000 miles from the area of concentration, and may well increase rapidly thereafter to what have heretofore been regarded as fantastic ranges.
Whether developments such as this will eventually threaten the supremacy of sea power, as envisaged by Admiral Mahan, is a question of great importance to the United States, for at the moment that our industrial areas become vulnerable to long- range aerial bombardment, at that moment do we lose the fancied protection afforded by our hitherto geographically isolated position. At that moment we shall be forced in self-defense to prohibit the erection of air bases within range of our coasts, and to maintain a sufficient air force to repel all long-range attacks. It is evident, for these reasons, that we must not only vigorously prosecute the procurement and training of an extremely powerful air force, but we must likewise prepare public opinion for the eventual and inevitable end of our long era of safety and isolation.
As the ground swell from the European tempest of destruction surges across 3,000 miles of ocean to our shores, it should warn us of the menace to our safety and the threat to the survival of our freedom. In these days of undeclared wars, we should realize fully that war may come to us at whatever time our potential enemies can find a place at which, and a weapon with which, to strike. It will not require an Act of Congress to involve us in hostilities; in all probability we shall find ourselves involved at some unexpected moment and at some unexpected spot. We have seen examples of the penalty for failure to be prepared. Defeat is the penalty for that failure, and oblivion is the penalty for defeat. We must achieve in unity, and with courage, and at the maximum speed attainable through our high industrial skills, the utmost effort for preparedness.
We must brook no interference with this effort, remembering that even if it proceeds on schedule the limits adjudged to be the minimum requirements necessary to assure security will not be reached for many months, and that until they are reached we may at any time face the most critical dangers in the history of our nation.