Contemporary conflictuality makes us rediscover that war in cities, places of concentration of power and population, is the real issue in today's conflicts. Lieutenant-Colonel Laurent Luisetti shows that it would be risky to think that it is possible to engage in urbanised areas without special operational preparation and a solid doctrinal basis. The urban area must be approached as a singular environment in its own right, in which the combatant must possess the appropriate know-how.

If armies have always fought for cities, fighting in cities is quite recent. In this respect, the myth of the Trojan War is misleading, as the fighting that took place within the fortifications, after ten years of siege, was finally of low intensity. It was the 20th ^century, with its procession of industrial wars, that truly marked the entry of war into the city. Does this mean that the war will now take place only in the city and that we can expect a radical paradigm shift in our approach to air-land combat? Probably not. However, the capabilities of observation, detection, indirect and aerial fire make the confrontation of military forces in open areas less likely and less relevant. For it is a fact: contemporary conflictuality makes us rediscover that war in cities, where power and population are concentrated, is the real issue in today's conflicts. It is because it attenuates the technological differential and because the presence of the inhabitants is permanent, a presence that imposes limitations on the use of force, that the city brings the belligerents closer together. Distances of engagement are reduced, surprise and tactical inventiveness become the norm. Manoeuvring skills and the ability to withstand blows are skills that ground units must have in order to win.

Modern armies therefore have no choice but to equip themselves with the means to prepare for engagement in urbanised areas and confined spaces, tools that are necessary to operate effectively and win in the long term. This observation led to the creation of the CENZUB-94 RI[1] in 2005, born of a need that was felt at the turn of the century during the rebuilding of Central Europe. Today, the formula adopted by the Army makes it possible to go beyond this initial vocation and places the centre in a position of scout which enables it to ensure operational preparation for today's commitments while anticipating those of tomorrow.

The existence of combat training centres in urban areas is justified by several objective reasons. The first, and most obvious, is that urban areas are usually the centre of gravity of the adversaries. The war is making a resounding comeback there.

"...] In the midst of uncertainty, one invariant persists: whatever the threat or risk, the population and the cities in which it resides are at the heart of interventions. They are often at stake, sometimes hostage to it. How could it be otherwise when in 2030, 60% of the world's population will be urban dwellers" [2].

In 1950, the UN estimated the urban population at 30% of the population. In 2008, for the first time in history, more than half of humanity is urban. This trend is continuous and, while the number of megacities [3] continues to grow, there is no indication of a potential inflection in the foreseeable future. It is therefore illusory to imagine that the case of the Battle of Falluja, emptied of its inhabitants in 2004, is not an exception in contemporary military history.

Because of their disproportionate size, these cities will bear the seeds of certain fragilities that will make them susceptible to crises of various kinds: economic, health, food, climatic or technological, with logical extensions in the field of security. As recent conflicts have shown, in order to defeat an enemy that relies on the urban fabric, hidden among the population, the commitment of land forces to ensure control of the environment is essential. Air or indirect strikes alone produce limited effects, sometimes counterproductive and potentially recovered by enemy propaganda. In this respect, during the Battle of Aleppo (2012-2016) in Syria, the various protagonists used images taken after bombings[4] for operational communication purposes, the effects of which on the inhabitants were sometimes difficult to measure. On the other hand, the rate of destruction of combat zones is a factual data, a corollary of all urban engagements. Recent fighting in cities has resulted in their partial destruction. Marawi, Aleppo and Mosul are now nothing more than heaps of ruins in some of their neighbourhoods, thus creating an unprecedented physiognomy of the combat zone, which is difficult to reproduce for training purposes.

This reconfiguration of the urban space, however, causes profound difficulties in terms of mobility, rhythm and therefore fluidity of the manoeuvre of the units that will have to engage in it to flush out the enemy or protect the population. It is impossible to free oneself from this roughness of the environment without being specifically prepared for it.

It would indeed be hazardous to think that one can engage in an urbanized area without a particular operational preparation and a solid doctrinal background. The urban area must be approached as a singular environment in its own right, in which the combatant must possess the appropriate know-how. Fighting in the depths of an urban area requires certain skills to free oneself from physical constraints and break the enemy's will through the combination of inter-service effects.

It's not just a question of densification and population concentration [5]: the very face of the city is changing. It thickens and grows both above and below ground. The urban area should not only be read horizontally as a space organized in concentric circles of decreasing permeability, but should also be read vertically as a superimposition of layers. It is therefore an environment in its own right, with special characteristics.

By its very compartmentalized nature, it is an environment in which:

• The verticality of the infrastructure means that you have to fight simultaneously on several levels.
• One faces a highly reactive adversary who can resort to modes of action from "weak to strong", taking various forms, and who poses a permanent and omnidirectional threat to the combatant.
• It is often fought at short and very short distances, with numerous losses and a high consumption of resources.

It is an extremely demanding environment, both physically and psychologically, in which the prospect of seeing the enemy appear where it is least expected requires strong moral fortitude.

In order to solve the specific tactical problems encountered in the city, mastery of certain modes of action and adapted combat procedures is imperative.

The practice of combat in urban and confined areas has not generated a tactical revolution per se, and the principles of warfare apply to it with the same relevance as in other environments [6]. [6] To this is added reversibility, which makes it possible to act on the entire spectrum of missions by applying the principle of subsidiarity in the spirit of the Three Block War concept,[7] and legitimacy, which ensures the support, or at least neutrality, of the population.

On the other hand, combat in urban areas requires careful consideration prior to engagement. This leads to a detailed preparation of the mission, embodied by the design of numerous coordination measures, and to choices in terms of the articulation of inter-service means that are different from those that would be used in other environments. It is accepted that the balance of power in favour of winning in ZUB is of the order of six to one to ten to one locally. It is therefore easy to understand that this ratio cannot be obtained solely by mass in an environment that compartmentalises and channels. Far from clichés, the city is not just a matter of infantry. The Israelis have understood this for a long time, for whom, in the city, "armor is not anoption".

It is therefore the synchronisation of the effects between the weapons that will create the conditions that will allow the enemy to be pushed around, especially if the enemy has laid out the ground, hardened his positions, trampled on the enemy's weapons, and so on.The synchronization of interarmy effects will create the conditions for pushing the enemy around, especially if the enemy has cleared the terrain, hardened its positions, trapped the routes and prepared counter-attack routes (via openingsin buildings or tunnels dug underground). This integration between weapons brings mobility, firepower and protection to the fighter. It can be practiced, if necessary, down to the lower tactical levels (platoon or section, or even combat group). It is this combination that contributes to maintaining the pace of the manoeuvre, as it allows the acceleration of actions in a combat situation that is by nature decentralised, and which protects combatants from new combat techniques such as suicide attacks or the threat of UAVs, whether flying or ground-based. It is not static and, in addition to infantry, cavalry, engineers and artillery - which form the core of the joint forces in urban areas - it is not fixed.other capabilities, such as intelligence, electronic warfare and influence, contribute to the effectiveness of units operating in cities.

That is why, in order to meet the challenges posed by the urban area, many countries are setting up dedicated training centres.

France has made an original choice. To prepare the engagement of land forces in urban areas, CENZUB-94 RI is conducting three main actions:

• It provides training in the combat procedures and specific know-how necessary to maneuver and fire in urban areas, as well as training for engagement in contact with crowds.
• It trains: in an environment which is necessarily inter-service and which tends to be open to actors outside the field of conventional forces.
• It conceives: thanks to its studies and prospective cell, it elaborates the doctrine for the use of land forces in urban areas at reinforced level 6 [8] and level 5 [9], and conducts tactical and technical experiments.

It is a global, innovative and unique concept, which makes it an internationally recognised expert centre.

With what and how? To fulfil its missions, it has organic, material and human resources, and implements an adapted pedagogy that ensures that the units make sure they progress during their time at the centre. It is indeed impossible for units to train independently and in garrison. Only the CENZUB-94 RI offers a realistic training environment and conditions in accordance with the "train as you fight" principle. The centre has the infrastructure, but also and above all the expertise that lies in the knowledge of the instructors and the skills of the opposing force company (FORAD), as well as the simulation means that are indispensable for training.

In this case, it is a so-called "instrumented" simulation. Everything is real: the environment, the men, the equipment; only the effect of the weapons is simulated [10], via a system of laser transmitters and receivers. This device is very powerful, however its capacities will be multiplied with the Cerberus program [11] which will bring the CENZUB-94 RI into the 21st century. Cerberus will increase the realism of operational readiness by simulating the effects of all weapons, including those with area effects and those that allow firing beyond direct sight. The effects will be rendered by pyrotechnics, sound and light. In addition, all actors on the battlefield, combatants and vehicles, will be geolocated, including in buildings. This represents a real technical feat which, combined with a central system, will enable the centre's instructors to prepare even more precise and relevant after-action analyses for the units being trained.

These analyses conclude a pedagogical process specific to the centre, called "accompanied learning". For two weeks, instructors from all operational functions involved in actions in urban areas will follow the units with professionalism and kindness. They are therefore the same ones who instruct and evaluate. The bond of trust gradually created ensures the transmission of messages that will help the unit progress, in a form of maieutics. The practice of joint arms is the keystone of this teaching. It is the conclusion of a rigorous intellectual approach which aims at methodically analysing a whole range of diverse information to help leaders at all levels to make decisions and consolidate their capacity for initiative. Furthermore, the sustained sequence of tactical sequences is conducive to the sharpening of the troop and helps to soak the character of leaders who must overcome friction and decide in the fog. This intellectual agility, which is necessary to maintain the rhythm, guarantees the optimisation of the means available to tactical leaders, a sign of a certain plasticity of the units, which will be further enhanced by infovalorisation.

Finally, the CENZUB-94 RI is a laboratory of excellence with which to prepare for the future.

If war is a chameleon, the centre is in permanent mutation. It is constantly developing in order to keep up with the evolution of today's conflict and to think about tomorrow's combat. For example, areas of ruins have completed the panel of training areas in the first half of 2018, a complex of combat in an underground environment on several levels will be created before 2019. In parallel with the construction of these complementary infrastructures, doctrinal reflections and technical-tactical experiments are being conducted to maintain the advantage in these particularly confined environments. It is indeed a question of placing oneself in an exploratory logic and anticipating the needs of land forces in terms of means and procedures. We must also remain attentive to the contributions of technological innovations, both military and dual-use, such as drones, robots and augmented reality. Finally, CENZUB-94 RI is directly involved in strengthening synergy with multiple actors: interoperability with French special forces and international partners and cooperation with internal security forces[12].

[12] Combat training centres in urban areas are indispensable. Military personnel, whatever their nationality, make no mistake and look with great interest at the French example[13]. 13] These centers, if they respect the triptych infrastructure-expertise-simulation, are the guarantee of future success.

1] Training center for actions in urban areas - 94th infantry regiment^, stationed in Sissonne.

2 ] General Bertrand Ract-Madoux, in Lettre de liaison des UED universitaires (June 2013).

3] A conglomeration of more than 10 million inhabitants.

4] "False Images and Propaganda of the Battle of Aleppo", Samuel Laurent and Adrien Sénécat, www.lemonde.fr, December 15, 2016.

5] According to the UN's World Urbanization Prospects, there should be 41 megacities in 2030.

6] The principles of war according to Foch: freedom of action, concentration of efforts, economy of means.

7] Concept described by General (US) Charles Krulak in "The Strategic Corporal:Leadership in the Three Block War (1999)", to illustrate the increasing complexity of modern operations, which lead to simultaneous actions covering the entire spectrum of missions in contiguous spaces.

8] Reinforced section or platoon

9 ] Joint Battle Group (JBG) Sub-Group

10] With the exception of the urban shooting complex (CTZUB), a structure dedicated to the practice of live ammunition shooting.

[11] Training centres representative of the battle areas and commitment return areas, notified by the DGA on 30 December 2016.

12] For example: training of BIS-PP intervention groups in 2017 and 2018.

13] Opening of the UAE centre in 2014, Germany in 2018. Projects in Asia and the Gulf.

After graduating from the École militaire interarmes, promotion "Captain Coignet" (2000-2002), Lieutenant-Colonel Laurent LUISETTI chose the infantry. He served successively in the 92nd, ^then in the 152nd infantry ^regiment. Graduated from the 23rd ^{class of} the War School, he is currently head of the training and instruction office of the Training Center for Actions in Urban Areas - 94th Infantry Regiment.