Washington Naval Treaty 2.0

Continental School: The main representatives of the so-called ―continental school‖ of naval strategy were French Vice Admiral Raoul Castex (1878–1968) and German Vice Admiral Wolfgang Wegener (1875–1956). Castex, whose ideas on naval strategy were broader and more universal, was a more methodical and deeper thinker than Wegener. Wegener’s focus was too narrow because his main and almost sole concern was Germany’s unfavorable geostrategic position at sea and how that situation could be improved in a future major conflict on the continent.

Vice Admiral Raoul Castex: Castex borrowed Mahan’s historical method on the centrality of sea power and the primacy of the battleship fleet. However, in contrast to Mahan, Castex’s work was focused on strategy as a whole, not solely on naval strategy.50 He was a prolific writer. His main work was the five-volume Theories Strategiques (Strategic Theories), published between1927 and 1935.51 The immediate impact on the French Navy was rather insignificant. Only many years afterward, French naval officers realized the true value and importance of Castex’s strategic ideas. His work was widely respected and accepted in many navies of Latin America and in the Mediterranean. Abbreviated versions of his works were published in Yugoslavia, Greece, and Soviet Russia.52

Castex wrote that in addition to land and naval strategy, there is also what he called general strategy (strategie generale) (or in today’s U.S. terms, national security strategy), which transcends and coordinates them. In his view, general strategy unites the actions of armies and fleets whenever the two types of forces must work together. 53 Castex correctly explained that strategy, like a war, is an art not a science. In his view, ―science evokes an element absolute certainty, of relations of cause and effect crystallized into rules so invariable and rigid that they become veritable laws, governing everything and impossible to escape. A scientific law asserts that the same scientific observation will always give rise to the same result, just as mathematical formula generates the same answer whenever the same numbers are used.‖ In his view, ―the simple principles that govern strategy are not chains but flexible guides leaving free play to the creative imagination and to the human spirit in situations that are themselves enormously variable. Precisely here lies the essential character of art—which never entirely breaks free of principles not even of rules but still manifests itself in an unlimited variety of ways.‖ He was right in stating that art has not country and that the ―artistic point of view allows us to behold the great strategic writings regardless of their time or place or origin, with admiration and envy.‖ 54

Castex held highly contradictory views on the proper relationships between strategy and tactics (he did not recognize operational art as a component of military art). To Castex, strategy was ―nothing other than the general conduct of operations, the supreme art of leaders at certain level of the hierarchy and of the general staff that serve them. Strategy prepares the battles striving to bring them about under the best conditions to bring about the best results.‖ Castex clearly confused strategy and operational art. He wrote that strategy ―links the battles together, controlling and coordinating them in accordance with the general inspiration of the campaign while reacting also to events.‖ He also argued that strategy dominates tactics prior to, during, and in the aftermath of a naval battle. He explained that [naval] tactics start ―only at the beginning of gunfire of the first cannon or torpedo, but one can hardly subtract from tactics all of the movements preliminary to the battle on the pretext that they belong to strategy.‖55

Castex asserted that ―strategy is everywhere at every level. It cannot be isolated as governing certain parts but is intermingled in the totality of war itself. There is no longer a strategic operation, since all military activity qualifies.‖ In his view, a commander is acting strategically when he conceives of an operation. However, since his orders must also prescribe the dispositions for the execution of these orders, he is performing tactically at the same time.
Likewise, the subordinate who acts tactically in executing orders must also act strategically in conceiving their execution. In contemplating dispositions for executing his plan, the supreme commander acts tactically. In making a fire plan to suit a particular case, a ship’s gunnery officer thinks strategically. Yet this definition leads in practice to the unworkable thesis that everyone at every level of command is simultaneously a strategist and a tactician.

Castex, like Mahan and Corbett, firmly believed that the main objective of, in his words,―maritime operations‖ was to obtain or at least to dispute the mastery of the sea, that is, thecontrol of the essential surface communications. The objective of naval war was to preserve freedom to use communications and deny the same to the enemy or ―at least, not to be entirely excluded by the enemy from their use.‖57 In his view, control of maritime communications has offensive and defensive aspects. Whoever controls sea communications preserves its links withoverseas. At the same time, control of maritime communications gives protection of one’s coast against major enemy actions.58 He recognized the great economic importance of having control of maritime communications for the continuous functioning of a nation’s commercial and industrial activity. He pointed out that the struggle for mastery of the sea is strongly related to the attack on and defense of communications. Castex wrote that the attack on and defense of maritime communications cannot be considered separately; they are closely intertwined and constantly affect each other. In his view, the [battle] fleet including even the air force, supports and sustains those parts of the navy tasked to conduct the attack on or defense of maritime communications. It is thanks to ―the [battle] fleet that they can operate without excessive hindrance of the enemy.‖ Moreover, the struggle for control of maritime war cannot be treated as ―a separate operation divorced from the rest of the military effort.‖ However, it cannot at the same time replace the struggle against the enemy battle fleet. In a clear rebuttal of the French Navy’s traditional fascination with guerre de course, Castex warned that ―one must not harbor the illusion that the attack on (the enemy maritime) communications will by itself and without any other operation lead to a decisive victory.‖59

Castex wrote that ―whoever wants to defeat the enemy fleet by combat must necessarily take the offensive without concern for its inherent risks. We need to concentrate as many forces as possible on the principal objective so as to have every possible advantage.‖ Only the offensive can definitely break the equilibrium to produce a decision. Only when accompanied with an offensive executed elsewhere can the defensive lead to a decision and the end of the status quo. The decisive character is the virtue of ―genuine offensive and only offensive capable of bringing about decisions are worthy of the name.‖ He disagreed with the views of those who believed that attack on the enemy maritime commerce alone would lead to the decision. He asserted that the guerre de course has never achieved significant results unless preceded or accompanied by a naval offensive. To achieve the decision, guerre de course requires support by the guerre militaire. Such actions cannot be decisive and hence cannot be properly called an offensive at all. He wrote that the same observation applies to attacks on the enemy coast and territories.60However, attacks on the enemy coast are actually the result of the stronger fleet’s success in achieving command of the sea, and they can be decisive provided that the fleet provides effective support to friendly troops on the coast. Castex agreed with Mahan that the enemy ―fleet must be defeated in order to obtain command of the sea.‖He wrote that one should direct all his actions against the enemy fleet because its destruction ―will very probably irreparably compromise the rest of the enemy’s organization.‖ The best method of disposing the enemy fleet is to wage a decisive naval battle. In case the enemy chooses to ―shut himself up in port then he has to be blockaded more or less tightly to prevent his emergence or to force him to battle as soon as possible if he does.‖ After having dealtwith the enemy fleet, the stronger fleet can exercise command of the sea by conducting other operations. Castex warned that the stronger fleet should not exercise command of the sea prematurely because that might undermine the freedom of action essential to the destruction of the enemy fleet. For him, the fleet and decisive naval battle ―constitute the cornerstone, the foundation upon which we will construct our plans.‖ Command of the sea is ―a military struggle between the belligerent’s fleets, that is to say, between the ensemble of their combat resources, including both naval and air forces under a single chief.‖ 61

Castex considered what he called ―strategic maneuver‖ (actually combination of strategic deployment and operational maneuver) as the centerpiece of his strategic theories. In referring to what is commonly understood as strategic deployment, he wrote that the French navy should accept [decisive] battle only after using maneuver to create a favorable shift in the naval balance.62 At the same time, strategic maneuver was for Castex a key element in the conduct of an operation. Thus, he clearly confused strategic maneuver with strategic deployment/redeployment. He wrote that strategic maneuver is a method used by strategists to ―improve the conditions of the struggle [at sea], to multiply the return on her efforts and to obtain the greatest results, whether in the duel between the principal forces themselves or to the benefit of particularly important non maritime requirements.‖ In referring to what is an operational maneuver, Castex wrote that ―movement is the primary element of manouevre—it is the movement to achieve desired dispositions. Then it is the movement of the principal and secondary forces to exploit the situation thus created and to execute the manoeuvre.‖ Castex observed that strategic maneuver ―above all demands space.‖ However, because the ―advent of new machines has compressed both linear dimensions and time, manoeuvre now finds new obstacles.‖ Strategic maneuver can be conducted only in a large sea/ocean area offering sufficient space for a maneuver; elsewhere, maneuver is notably more limited though not absolutely impossible. Castex wrote that the ―logical result of manoeuvre can only be to affirm superiority at the chosen point.‖ When the maneuver is directed from the outset against the enemy fleet, the purpose is nothing other than battle, which is in his words ―the summit of the edifice.‖63

Unlike Mahan, Castex clearly recognized that in some situations even an offensive plan must provide for a possibility of conducting a defensive in a certain part of a maritime theater. Except in a situation where one’s naval strength is overwhelming, it is simply impossible to be ―superior at a chosen point without being weaker, and therefore on the defensive elsewhere.‖ The defensive is often combined with the offensive in time as well as in space.64 Castex correctly observed that in a war between the two continental states bordering the sea, ―mastery of the sea is, at least in theory, no longer even a necessary condition, since the issue of the hostilities will finally depend on the result of the combat between the land armies.‖ Yet ―command of the sea will most often have a serious effect on the operations of these armies and it will be useful to the power that holds it.‖65

Like Corbett, Castex believed that there is no such thing as total command of the sea. The maritime theater of operations, unlike the area of land operations is ―constantly traveled by strangers to the conflict.‖ Command of the sea ―is not absolute but relative, incomplete and imperfect. In spite of crushing superiority, the dominance of communications has never completely prevented his enemy from appearing on the water.‖ Even relative mastery of the sea cannot be exercised at all points of the globe at the same time because even the strongest power lacks sufficient force. There has never been general control of sea communications but only local control over specific parts of the theater or fewer in number, to a greater or smaller extent, and depending upon one’s resources. Sometimes geography and the distribution of fleets shifted local control of the sea to the benefit of the weakened navy. Castex asserted that freedom to use the sea for one’s purposes ―confers opportunities for coastal raids, seizures on the high seas and conditions permitting old-fashioned blockade.‖ By achieving sea mastery, the stronger side can ―paralyze or at least restrict the enemy’s links with foreign countries. It can attack the enemy’s coast and exploit the advantages offered by conduct of ―combined‖ [actually multi-service or joint] operations and dictate the enemy intercourse with neutrals in the conflict.‖ 66

Castex wrote that the very term command of the sea ―gives the impression that its beneficiary enjoys the marvelous privilege of having to himself the immense expanse of the oceans or building a sort of barricade whose keys put in his pocket these totally banning peacetime users. This is misleading. It is utopian. All of the world’s united fleets would not suffice to achieve it everywhere. Nor would neutrals easily allow themselves to be cut off from trade.‖ In his view, one’s strategic command of the sea very often requires a forced decision about attacking or even invading the enemy’s coast. The term command of the sea is less meaningful than in the past, and it is more precise and less pretentious to speak henceforth only of the mastery of the surface, but in a restricted sense, as we think to master the sea. It is a new dilution, another step on the road to relativity.67

Castex had unfavorable views of the fleet-in-being concept as a means of contesting command of the sea by a weaker navy. He explained that it is ―excessive temerity for the inferior party to sail out into battle and destruction one cannot found great hopes of the method of the fleet in being against an active, enterprising adversary who is knowledgeable of his profession.‖ He agreed with Mahan’s view and disagreed with Corbett on the usefulness of the fleet-in-being concept. Castex asserted that the errors of the integral doctrine of the fleet-in-being concept consist of the belief that the mere existence of such a fleet suffices to produce an effect, even if said fleet is moribund, and that it will necessarily paralyze a superior enemy who is master of the sea.68

Castex gave much attention and thought to the effect airpower would have on the conduct of war at sea. He was perhaps one of the first theoreticians who believed in the possibility of employing aircraft against enemy maritime commerce and commercial ports. Such attacks will ―constitute a much greater novelty than air attack on commerce at sea.‖69 In his view, air mastery is even more relative than mastery of the sea, and the master of the air cannot hope to forbid it completely to his enemy by any permanent occupation of its three dimensions. The mastery of the air is even at a further disadvantage in this regard than the master of the sea because he can never prevent the airplanes of even the weakest adversary from conducting reconnaissance or even bombardments and then disappearing as quickly as they come.70

Castex wrote that the employment of ―the airplane against [maritime] communications will vary completely depending on whether they act against convoys or against isolated ships.‖In his view, escorted convoys can be attacked ―without hesitation, as a military formation because they leave no uncertainty as to their nationality. He was highly pessimistic as to the ability of a convoy to defend itself against an attack from the air. He asserted that the ships in a convoy are usually large, slow and unmaneuverable, and lacking antiaircraft protection.‖ Castex properly observed that if used, convoys would require strong air cover.71 ―There are no sufficient resources to provide too many convoys with the necessary protection.‖ In his view, the number of convoys must be reduced to minimize the number of aircraft required for their defense. At the same time, a ―system of huge and infrequent convoys is unworkable and the necessary concentration of air escorts can be managed if one has the initiative of operations. Castex properly observed if used, convoys would require strong air cover.72 The Allied experience in World War II in the Mediterranean and in the Arctic proved the validity of Castex’s views on the use of convoys in the face of the threat posed by the land-based aircraft.

Castex was more optimistic in the chances of merchant vessels surviving an air attack by sailing singly. He stated correctly that aircraft would be unable to force a ship to stop and identify itself, yet he wrongly believed that ―an airplane can easily be deceived by false signals, false flags, and camouflage‖ and that a blacked-out [merchant] ship would have a good chance of escaping the airplane at night. In his view, there ―does not seem to be any compromise between large convoys and the individually sailing merchant vessels. World War II proved wrong Castex’s view on the viability of using merchant vessels sailing singly not only in the littorals but on the open ocean as well.

In contrast to Mahan but like Corbett, Castex firmly believed in the need for close cooperation between the navy and the army. He explained that the ―relationship between the army and the navy must be as between infantry and artillery. As is infantry the queen of battle so the army is the queen of general strategy. Everything has to be subordinated to it because its success means the success of the general strategy. The navy is often to the army as the artillery is to the infantry; an indispensable support that allows it to accomplish its objectives.‖ He correctly stressed that the success of land operations is, after all, what matters the most. Only victory on land permits the occupation of the enemy territory and would convince the enemy that he is defeated. For Castex, the importance of sea power is directly related to its contribution to the victory on land. Only in exceptional cases can sea power achieve complete victory by itself.74

Castex highlighted importance of geography or physical environment on the conduct of war at sea. He wrote that an attack on and defense of sea communications is heavily affected by geography.Geography provides or withholds positions from which commerce raiders can base their action. It also provides a means of establishing a blockade. In the littorals, hydrography can serve the defender by protecting his coastal communications and hiding them from the actions of the attacker. The outer islands belonging to the defender constitute positions of defense behind which coastal traffic can circulate in more secure conditions; the defender also possesses internal channels or navigable canals, reefs and shallow water. In Castex’s view, the influence of geography on maritime operations is not constant but evolves with technological advances. For example, the water depth affects strategy (actually more accurately naval tactics and to some extent operational art) because of the ―consequences of employing submarines, mines and underwater obstacles.‖75

Castex’s main contribution to naval theory was his insistence on the need to have the conceptual foundations in order to have a sound naval strategy. Such foundations must be transparent and resilient; otherwise, they would not endure under the changing conditions.Castex believed that the absence of a coherent, historically grounded understanding of strategy ―prevented the smooth assimilation during Great War of events that instead created in many minds a profound and unnecessary upset.‖ Like Mahan, he believed in the validity of the historical method in developing a naval strategy. At the same time, in contrast to many of his contemporaries, he recognized that Mahan’s prescriptions must be modified to fit specific national circumstances and materiel conditions. Castex believed that historical principle was the best but not the only source of truth, and that advocates of materiel made an error in their single-minded focus on technology. Yet at the same time, they also offered a useful corrective to the historians’ tendency to think at a level of abstraction that avoided actual discussion of the conduct of war. He firmly believed that naval strategy must acknowledge both historical principles and materiel conditions.76

“The history of sea power is largely, though by no means solely, a narrative of contests between nations, of mutual rivalries, of violence frequently culminating in war. The profound influence of sea commerce upon the wealth and strength of countries was clearly seen long before the true principles which governed its growth and prosperity were detected. To secure to one's own people a disproportionate share of such benefits, every effort was made to exclude others, either by the peaceful legislative methods of monopoly or prohibitory regulations, or, when these failed, by direct violence. The clash of interests, the angry feelings roused by conflicting attempts thus to appropriate the larger share, if not the whole, of the advantages of commerce, and of distant unsettled commercial regions, led to wars. On the other hand, wars arising from other causes have been greatly modified in their conduct and issue by the control of the sea. Therefore the history of sea power, while embracing in its broad sweep all that tends to make a people great upon the sea or by the sea, is largely a military history...”


― Alfred Thayer Mahan, The Influence of Sea Power Upon History, 1660-1783