Man is also the enemy. Let us come to him, since he is generally the essential provider of opposition, of friction against our own will. For General Beaufre, "strategy is the art of the dialectic of wills using force to resolve their conflict.⁴⁰"Just as we do, the adversary sets goals for himself, which he usually tries to conceal. He develops a maneuver, not always direct, nor forcefully rational in our eyes. He can cheat, deceive, but also make errors of appreciation or mistakes in the conduct of his maneuver. The uncertainty induced by the enemy is all the greater as it can be multiple and changing.

The context of some of the operations of the last few decades, where the Force has found itself in a situation of interposition between factions, has often provided an example of this.⁴¹. In these respects, the analogy between war and chess is ultimately misleading. In the first place, the transparency of the battlefield and the balanced balance of power only between two players in chess, are generally not found in war. In addition, the "closed world" represented by a chessboard limits the unfolding of the games, even if the possibilities are considerable⁴²and gives players the opportunity to learn, anticipate and reproduce "moves". However, the enemy is always surprising, all the more so since since medieval times, the battle no longer takes place in an enclosed field. The comparison with liar poker is then probably more appropriate. At the beginning of the game, multiple players have no certain vision of the resources of the various opponents, which they will use without necessarily following rules established in advance.

The actions-reactions of the players, especially in psychological registers, are therefore fundamental in trying to perceive the intentions of the opponents and potentially defeat them, if chance contributes to it. The American economist and strategist Edward Luttwak⁴³In a less trivial way, it conceptualizes this notion of action-reaction, by establishing a difference between the linear decision-maker and the paradoxical decision-maker. The linear decision-maker identifies the problems, qualifies them, elaborates the solution according to their nature and implements it. However, according to Luttwak, the linear decision-maker does not take into account the fundamental aspect of warfare that is the dialectic of wills. That is, the opposing intention and the reactions of the adversary to a decision taken. Thus, operational decision-making is not only about matching resources to objectives, but also, and more importantly, about making the adversary's reaction favourable. Otherwise, the chosen solution remains ineffective or even counterproductive. Faced with the linear decision-maker, Luttwak opposes the paradoxical decision-maker who integrates this dialectic of wills in his manoeuvre and takes into account one of the main imperatives of operational decision-making, namely : to act to degrade the decision-making capacity of the other. Finally, since the uncertainty is the same for both sides, the winner is the one who, through his limited rationality, his "glance and intuition, will know best and fastest how to take the initiative in decision making by masking his goals and potential, understanding those of the opponent, and thereby acting to counter his will.

In the same way, one of the keys to success in war is to get the adversary to reveal his intention, his device and his vulnerabilities, by provoking reactions, generally through contact and thus by committing resources, which are always scarce. The understanding of the adversary can thus only really be obtained during the action.⁴⁴ and previously goes through experience, and often through occasional failure. There is therefore systematically a cost to be paid to learn from the enemy, thus dispelling some of the fog of war and adapting one's own manoeuvres. This is what General Mangin summed up in 1920 when he said: "The enemy is a good teacher, but his lessons are expensive...⁴⁵. »

Thus, in all strategists since the eighteenth century, we note the paradoxical coexistence of two main currents, sometimes found in the same author, such as Jomini. The first trend is that of a philosophy of decision making that emphasizes military genius, the "eye" and instinct. The second trend establishes a theory of knowledge, which postulates the presence of scientific regularities. The exaltation of military engineering by the classical authors, and still today by the military institution, is not only due to the need to establish traditions and to offer models of virtue to new generations of officers. It reflects in a very pragmatic way the inability of purely scientific models to dispel the fog of war and reduce the friction generated by man himself.

A leader's intuition is thus the necessary compromise between a purely rationalist approach and a purely empirical approach to battle. The ability of a leader to free himself from the temptation of absolute rationality and to rely on his intuition in the face of circumstances, and therefore to take risks, would thus be the characteristic of a warlord. In Le fil de l'épée, Lieutenant-Colonel de Gaulle establishes that it is the chief's instinct that provides the concrete framework for action. "The essential role of the leader is therefore to appreciate the circumstances of each particular case. Because he knows them, measures them, and exploits them, he is victorious; because he ignores them, misjudges them, neglects them, he is defeated. It is on contingencies that action must be built."⁴⁶.

Here we find Machiavelli's famous Virtù. However," he continues, "instinct is not enough, you also need a strong capacity for synthesis, so as to give each factor its rightful place, a synthesis that generally reflects an aptitude that is not very widespread. Finally, synthesis is only fruitful if it is accompanied by a return to oneself, the power to abstract oneself from ambient pressures: "All the great men of action were meditators. All of them possessed, to the highest degree, the faculty of turning in upon themselves, of deliberating within.⁴⁷. Bergson at the same time professed exactly the same principles in his lectures. Contingency of action, the role of inner deliberation, the importance of fair judgment. Do we not also find in these aspects the whole Aristotelian concept developed in Nicomachean Ethics? As Jean Guitton pointed out⁴⁸the man of war and the man of thought are never far apart.

The staff, the indispensable tool for the leader's decision making in war. Command can be considered as an art, because, as we have seen previously, it is centred on the personality of a leader, on his talent, on his inspiration of the moment and ultimately on the expression of his personal intention. It is also a science, because it cannot be effective without methods, systems and organizations. Indeed, the ability to command operationally seems to be the result of a particular alchemy, the effects of which, moreover, are never acquired. Napoleon had weaknesses throughout his campaigns, which eventually led him to Waterloo. General Henri Navarre, held responsible for the disaster at Dien Bien Phu⁴⁹The first leader to be noticed and to have good judgment was in the First World War, in the Levant during the inter-war period, and again during the Second World War. Thus, a leader's ability to make decisions can be impaired or strengthened over the years. Like heroism, military genius may not be a constant in an individual. 50 and remains dependent on the circumstances and the environment. The decision-maker must therefore be able to be assisted in the exercise of his command by a small and immediate set of subordinates, facilitating his understanding of the environment and enabling him to conceive, execute his intention, and then develop it into conduct in the most efficient way. This is the role of a staff.

The great military leaders, from ancient times to the Renaissance, gathered around them a small group of advisers and experts to accompany them during their campaigns. They are often civilians temporarily assigned to the service of a monarch's armies.

These experts were mainly artillerymen (the Bureau brothers at the Battle of Castillon for example), engineers for bridge-building and for poliorcetics, which played a major role in the conduct of the war, supply specialists, messengers and clerics. The political and military consequences of the Age of Enlightenment and the French Revolution during the 18th century led to an increase in the complexity of the art and techniques of warfare. Until then, the leader could still contemplate the battlefield with the naked eye and give orders to his troops almost instantaneously by voice, pennants or the sound of trumpets or bugles. The increase in the number of troops required decentralisation, leading to the emergence of the divisional system with Guibert and an extension of the theatre of operations with the Napoleonic campaigns. The control of operations became more complex and required more expertise.

The margin of initiative and subsidiarity granted to subordinate levels also became fundamental to guarantee the realisation of the chief's intention, who no longer had the possibility of conducting operations "on sight". This intention must then have been clearly conceived and expressed in initial orders including precise coordination measures. The lack of precision in the orders given to Grouchy, for example, would be paid for dearly by the Emperor on 18 June 1815. The increasing complexity of the art and science of warfare was therefore reflected in the way command was exercised upstream and then during the battle. It became essential for the military commander to have a small group of officers specialising in the administrative tasks of an army in the field, capable of reading, discussing, explaining and transmitting the most complex orders, thus leaving him free to exercise his command.

The Austrians formalized such staffs at the beginning of the 18th century, during the reign of Empress Maria Theresa. In France 51It was at about the same time, under Louis XIV, that they appeared. Under Louis XVI, Ségur created the first corps of staff officers in 1783. Some of them, including Berthier, served the Emperor remarkably well. It was the Prussians, with the great reform of the army undertaken by Scharnhorst and Clausewitz following the defeat of Jena in 1806, who really gave substance to the staffs of modern European armies. From then on, the concept of staff corps evolved and designated specialists trained in the planning and conduct of operations at various levels of the military apparatus. The organisation of armies and command is changing rapidly throughout Europe. These transformations are being brought about by technical progress in the fields of transport, communications and intelligence and are considerably changing the way in which strategic, operational and tactical decisions are taken. It was at the end of the 19th century, with the telegraph in particular, and then the TSF at the beginning of the 20th century, that technical means made it possible to circulate information much faster than the movement of armies.

It is at this point that the amount of information available will truly exceed the capacity of a single individual to integrate all the information at his or her disposal. It then becomes imperative that the Commander-in-Chief of the Armed Forces be able to delegate some of the tasks previously assigned to him, while retaining overall control of operations. This control requires the development of an elaborate, secure and rapid communications system. This is the birth of information and communication systems (CIS). Officer training was also improved in order to adapt armies to modern warfare by creating efficient and reliable chains of command. The General Staff became a structure more specifically responsible for advising and assisting a general officer, synthesising information, synthesising information, and providing support to the general staff.The staff becomes a structure more specifically responsible for advising and assisting a general officer, synthesizing information, assisting in decision-making, organizing, planning, programming, establishing orders, controlling their execution, monitoring events and learning from them. This is the modern definition of a staff.

In France, it was with Napoleon that the general staff was set up as a real system, although it remained mainly confined to drafting the Emperor's orders and administering the troops in the field. Berthier, although a poor tactician but an outstanding organiser, conceptualised and set up this organisation, known as "en rateau", which still characterises most modern general staffs. Thus, until the end of the 1980s in the French army, the staffs were organised into offices. The first office was in charge of personnel management; the second, intelligence; the third, operations, training and employment; the fourth, logistics (transport, supplies, etc.). During the Algerian war, a fifth office was also responsible for psychological warfare. From 1917 onwards, American troops were integrated under French command and thus adopted the organisation and procedures in force in the French headquarters. The Americans kept this type of organization without major and lasting changes until the early 2000s. Let us go back a century. In 1818, Gouvion-Saint-Cyr renewed the specialized staff corps, which remained in existence until 1876, and created the school of application of the royal staff corps.

Drawing lessons from the defeat in the War of 1870, General de Cissey, Minister of War, decided in 1876 to create the Ecole Supérieure de l'Armée de l'Armée.This school included courses designed to prepare for staff and command functions in two years, as the Prussians did at the Kriegsakademie. This approach paid off and teachers from the superior school of war before 1914, such as Lewal, Maillard, Bonnal, Foch, Pétain, Lanrezac, to name but a few, contributed to the edification of staff officers, enabling Marshal Joffre to affirm in 1918 : "During the first weeks of the war, we could not have done what we did, if the big staffs had not remained like rocks in the middle of the storm, spreading clarity and composure around them.

They kept in the most exhausting work, in the course of a terrible moral test, a lucidity of judgement, an ease of adaptation, a skill of execution from which victory was to come. 52"Yet in 1940, the French staffs were totally outclassed by those of the Germans, whose reactivity was multiplied by an organization and use of communication skills that had been imagined in peacetime. Resting on the laurels of victory, the French were slow to integrate technological progress and the new conditions of modern warfare into the organisation of their command, making them progressively inoperative during the inter-war period. Marc Bloch is right to say that "an idea, in the field of positive science or technology, is only of value as an image or shortcut to concrete facts. Otherwise, it is reduced to its label, which now covers only a little of the void. 53 "The defeat of 1940 was therefore above all a defeat of thought, mainly that of our staffs.

The role of the Chief of Staff (COS) in this type of pyramidal organisation is essential for the coordination of the action of the offices and the anticipation of the actions to be carried out by the staff. As collective work requires procedures and standardisation of roles and production, the function of the COS also becomes that of guaranteeing the coherence and timely production of the orders required by subordinate units. The decisive roles of Berthier for Napoleon or Bayerlein for Rommel show the importance of the function. Sometimes a very close and complementary relationship can also develop between the operational chief and one of his direct assistants, as was the case with Weygand for Foch or Salan for de Lattre, to mention only the most emblematic pairs. These examples illustrate all the added value provided by trusting interactions between a leader and his or her immediate entourage. The hallmark of great chiefs is therefore to know how to surround themselves with officers capable of advising, understanding, interpreting, translating and implementing their intuition and will in practice. Evoking General de Lattre in Indochina, General Beaufre evokes this fundamental dimension. "Here, his method is truly personal: he prepared this elaboration by a careful choice of the men around him. It is with them, collectively, that he will gradually mature his decision. »⁵⁴

The term "staff" is now used in all complex organizations, large companies, administrations or political parties, to refer to a team of experts and advisors surrounding a decision-maker. So let us now look at the mutual influences that military theorists and those in sociology and business administration have had for more than a century.

The interactions between managerial theories and operational decision-making in warfare.

From the end of the industrial revolution, the large capitalist companies sought to break away from the family management model that prevailed at the time, by setting up organisations capable, in order to carry out large projects, of managing large numbers of people who were not always qualified. The only type of organisation known at that time, and which proved to be effective in carrying out multiple and complex tasks, was the military organisation. Through the contributions of the precursors of sociology and the first theorists of business administration, now called management, the large civil structures thus gradually adopted the methods of reasoning and organisation of the military at the beginning of the 20th century. Taking into account the hardening of competitive rivalries, the business world has, over time, adopted military decision-making concepts and their terminology. The hierarchical organization of most large administrations and companies today is thus a legacy and adaptation of military organizations. However, the story does not end there. Starting in the 1960s, US military decision-making methods and structures will in turn begin to be influenced by corporate administration methods, which have already incorporated advances in information systems. Integration into NATO during the same period will gradually normalise Western command structures on an American model, now strongly influenced by management theories. The search for good practice in both worlds, civilian and military, eventually gave rise, with varying degrees of success, to a number of experiments and adaptations foreshadowing what modern command systems and operational decision-making processes are today.

39 Damasio, Antonio, L'Erreur de Descartes : la raison des émotions, Paris, Odile Jacob, 1995.

40 Beaufre, André, Introduction à la stratégie, 1963, reprinted. Pluriel, 2012.

41 The interested reader may refer to the testimony of Colonel Hervé Pierre, recounting his experience in the Central African Republic in 2014, Tu massacreras vos frères! in Inflexions, n° 31, January 2016, republished under the direction of Lecointre, François in Le soldat - XXe-XXIe siècle, Folio, 2018.

42 The number of Shannon, that is 10120, is an estimate of the possible number of different games in chess.

43 Luttwak, Edward, Le grand livre de la stratégie: de la paix et de la guerre, Odile Jacob, 2002.

44 Interested readers may also refer to the series of articles about the enemy published in 2014 in Inflexions n°28 http://inflexions. net/page/5 and in particular the article by Colonel Frédéric Gout, recounting his experience in Mali in 2013, L'ennemi, cet ennemi, mon ennemi, republished under the direction of Lecointre, François in Le soldat - XXe-XXIe siècle, Folio, 2018.

45 Mangin, Charles, Comment finit la guerre, La revue des deux mondes, July 1920. http://www. revuedesdeuxmondes.fr/article-revue/vi-les-consequences-de-la-victoire/

46 de Gaulle, Charles, Le fil de l'épée, Berger-Levrault, 1932, reprinted. Le fil de l'épée and other writings, Plon, 1999.

47 de Gaulle, Charles, ibid.

48 Guitton, Jean, La pensée et la guerre, Desclée de Brouwer, 2017.

49 Report on the conduct of operations in Indochina under the direction of General

Navarre (Catroux report), cited in Gras, Yves, Histoire de la guerre d'Indochine, Denoël, 1979, reprinted. 1992.

50 Gabriel, Richard, No more heroes: madness and psychiatry in war, New York: Hille & Wang, 1987.

51 Interested readers may refer to Hittle, James, Donald, Les Etats-majors, leur histoire, leur évolution, Paris, Berger-Levraut, 1958.

52 Quoted in Jacques Deschamps, La guerre moderne (1885). A contribution to the strategic culture of the French staffs of the First World War, Revue stratégique, No. 99, 2010.

53 Bloch, Marc, The Strange Defeat, 1940, reprinted. Folio, 1990.

54 Beaufre, André, Le général de Lattre, Revue militaire d'information, 1962.