In order to preserve its workforce, Pétain very quickly obtained from the H.Q.G. that the large units making up the Second Army should not be organic, but that all the infantry divisions of the French army should turn to Verdun, so as to maintain a permanently high level of operational capability, with only the armature of the army corps remaining permanent.

(b) The noria

Thus, large units would be lifted before reaching a critical wear stage requiring complete rebuilding. This will be the "noria", with each large infantry unit rotating in the Verdun sector for less than a week before being raised and put to rest. Of the 104 infantry divisions then listed in the French army's order of battle, only about 20 were never committed at Verdun. The majority were engaged twice. This is the so-called "noria" system.

Thus, the army corps, which had previously become a large, expandable unit, i.e. one that could generate a variable number of divisions and elevations, was transformed into a large, flexible unit.Theoretically at least, the corps then becomes a grouping of interchangeable divisions and a permanent body responsible for ensuring the continuity of operations in a sector of the front.

Such an organization obviously provides considerable flexibility in the organization of command on the battlefield and the execution of reliefs. However, by accepting within each of these corps the principle of divisional transfers, the door is opened to frequent, if not continuous, changes in the order of battle. The indispensable organic links between the corps and the division are broken (just one example, neither the chiefs nor the staffs are no longer used to working together) and the result is a reduction in the output of the large units, the inevitable price to pay for the flexibility that this new organization induces.

To compensate for this disadvantage, the command was forced to make an eternal compromise between the need to maintain organic links and the desire to meet the constraints of battle management.

II-3. The inter-war period

The design agreed in 1919 was quickly modified to the following system. The corps now consists only of its command organs and organic elements. Depending on the missions entrusted to it, it can receive a variable number of divisions and reinforcing elements. On the other hand, the corps commander is always the commander of a region on whose territory a number of units are stationed which will not be included in the constitution of the corresponding corps when it is established. In addition, the border regions, which were formerly covering corps, now engulf the elements of the fortified regions (Maginot Line), which are now in charge of coverage.

Comparing with the previous table of 1914, an indisputable addition is obvious. In fact, from 60 years old in 1914, the average age has fallen to 55 and a half. In the meantime the age limit for generals had risen from 65 to 62. The consequence is obvious: Lieutenant Generals will continue to hold positions of responsibility on average for another six and a half years after the Armistice. By the same token, the average age of the generals commanding the armies had fallen from 62 in 1914 to 54 and a half in 1918, one year younger than their direct subordinates. This means that the prospect of advancement of Lieutenant Generals to a fifth star is, barring exceptions, nil! There were only two exceptions: Naulin and Nollet. The first will be superior commander of the troops in Morocco during the Rif War, which explains his promotion. The second had clear political affinities. Close to the Socialist radicals, he was Herriot's Minister of War at the time of the Left Cartel. What is true upwards, will also be true against their immediate subordinates: the divisionaries of 1918, with a few exceptions, the most emblematic being Gamelin, will also see their future blocked. In fact, as a result of the general rejuvenation that marked all the ranks of general officers during the war, the system was blocked and it was not until the late 1920s and early 1930s that a generational changeover of generals took place. This state of affairs will have two consequences!

The first will be the establishment of a real "magisterium bleuhorizon" on the French army until the early years of the twentieth century.es thirty (Pétain will be vice-president of the Council until 1931 and Gouraud, for example, undeniable GMP, member of the Conseil supérieur de la Guerre until 1938). Military thought was to be fixed on the "recipe" for victory. The continuous front, the avatar of the tyranny exerted by fire during the war years will be elevated to the rank of dogma, without taking into account, for example, the lessons of the war - of movement - on the Russian front.

The second is a military "brain drain". Exasperated by the conditions of advancement imposed on them, the best generals of the next generation will be forced to leave the country.Exasperated by the conditions of advancement imposed on them, the best generals of the next generation are sent on missions and embark on new careers, often in the industrial world, where they will succeed very well, like General Duval, the "General of the Army". like General Duval, the "father" of the Air Division after having been the much appreciated Chief of Staff of Fayolle or Estienne, " father" of tanks (the B1 tank he launched in 1922, before resigning, will still be in an experimental state twelve years later). As for General Tanant, the incomparable Chief of Staff of the 3rd Army during the war, a 49-year-old brigadier general in the Armistice, he was to "stagnate". six years in the subordinate command of the École de Saint-Cyr, before taking command of a division, and, at the extreme limit of his career, that of a military region.

II-4. The Second World War

During the 1940 campaign, the engagement of the corps was carried out in accordance with pre-war doctrine. It retained the predominant place that it held in the conduct of the battle: the richness of its staff, the volume of its orga nical elements (weapons and services), made it the large joint unit capable of manoeuvring in several directions, carrying out prolonged actions and winning the decision.

The American army corps (and therefore the French army corps of 1943-1945, totally identical) is a very strong structure, in order to be able to engage the means of combat and support that strengthen divisions or reinforce situations. The first complete logistical level, it is also the level of a volume of support and services that far exceeded anything that was then being carried out in Europe.

Logistics is designed both to cope with the highest levels of consumption according to the standards adopted and according to criteria that use power to crush the enemy. It must also provide all that is necessary for American units that are going to fight, by definition on foreign soil. No stock-outs can be envisaged and, for Eisenhower, logistics determine the operational decision.

As far as the CPs were concerned, the number of vehicles and radio equipment (especially voice equipment) were more plentiful than ever before: in this area, the Allies regained a clear advantage over the Germans. But, as a result, the PCs with their vehicles bristling with antennas became imposing targets, all the more so as they had to be deployed on high points, the links being made from "station to station". This explains why, from the army to the divisional level (i.e. the "High" and "Low" links of the corps), telephones are systematically installed with exchanges.

On the Western Front, for the allied armies, if the battle was conceived at the Army level, as in the previous conflict, it was conducted at the Corps level. Thus in the American army, after the breakthrough of Avranches, Patton split his army by launching a corps ofcorps in Brittany to Brest, a corps towards the Loire, to Orleans, then towards Troyes, and a corps in Brittany to Brest, a corps towards the Loire, to Orleans, then towards Troyes, and a corps in Brittany to Brest.army to branch off after Le Mans towards the North to - badly - close the Falaise pocket; in the British army, it is the 30th ofHorrocks (who left his career there) who failed to reach Arnhem by land; de Lattre with the First Army is not to be outdone: each of his two army corps participated in the pursuit of the 19th German army, on both sides of the Rhône from Provence to the threshold of the Vosges. Then, the battle of the Vosges was that of Monsabert, while the battle of Upper Alsace was that of Béthouart.

As for the Soviet army, it deliberately ignored the corps level. This is due to an upward stretching of the levels of command: Since it was the Soviet school of thought at the Frounze academy that identified and codified the art of operative art, it is not surprising that it was the Soviet school of thought thatThis led, as early as 1942, to the multiplication of "fronts", in fact groups of armies, to which the application of this operative maneuver was entrusted. The immediately subordinate level was the army, and directly below it the divisions that benefited from the effects or directly from the adaptation of the Army's support.