The "oil stain" strategy dear to Gallieni and Lyautey is still today unanimously accepted in stabilisation and counter-insurgency operations.⁹. Proof of this is its adaptation in the Anglo-Saxon doctrine within the quadriptych " shape, clear, hold, build ».

The oil-spot strategy consists of advancing progressively towards the insurgent zones, having first firmly secured all the rear lines: "only put one leg up in the air when the other is well seated" .¹⁰. To do this, the loyalist forces move within the population. Constraint but also opportunity: this makes it possible to convince the population of the legitimacy of the operation, particularly during patrols or during meetings at "checkpoints". Incidentally, the population becomes familiar with the soldiers surrounding it, who then become real local intelligence sensors and quickly gain the trust of the population.¹¹. The confinement of NATO troops in Afghanistan in Forward Operational Bases (FOBs )¹² justified by the great aggressiveness of the Taliban militias...¹³This has done little to gain the confidence of the non-insurgent population. Because it requires reaching out to the population, counterinsurgency is a militarily risky strategy, as soldiers are much more exposed to the public.¹⁴. It is also politically risky, as the acceptability of human losses is decreasing in Western public opinion.

Tactically, counter-insurgency also has its own characteristics, with adaptability being the key word. Indeed, each counterinsurgency is unique, has its own factors, both endogenous and exogenous, and must therefore be treated differently. Nevertheless, because the insurgent often has an unfavourable balance of power (more in terms of means and capabilities than in terms of mass) compared to loyalist forces, it will generally opt for guerrilla or terrorist tactics. Avoiding direct confrontation or limiting it to space-time frameworks that are favourable to it, the insurgent cannot be fought as conventional forces are. Moreover, Gallieni and Lyautey, as well as Templer, draw the conclusion from this that it is necessary to reject large-scale actions whose heaviness allows for warning the insurgents beforehand and will favour their flight (moreover in an environment that they better master). The military leader of a counter-insurgency will therefore have every interest in advocating the formation of mobile columns through which he will be able to chase the insurgents. Thus, as against any enemy (but perhaps even more so for an insurgent who refuses unfavourable battle conditions), it is by adapting to the enemy, the terrain, and the human environment that the leader will create the conditions for victory.

Today, while these precepts remain, their application has evolved in line with technological developments. Already in Malaysia, Templer is making massive use of the British Special Air Service. These soldiers trained in jungle combat give General Templer a deep projection capability to prevent any sanctuarisation of the insurgents by constant harassment. Even today, special forces are still employed to accomplish these objectives. The use of the third dimension through air-land or even joint operations brings even more mobility and an undeniable psychological effect on the enemy. Thus, air assets (Atlantique 2, Rafale, Fennec), although few in number, brought great agility and undeniable freedom of action to the French forces of Operation Sangaris, as well as non-negligible fire support . With a small number of troops (2,000), the latter had to demonstrate constant adaptability and great reversibility in order to achieve their objectives.¹⁵.

This reveals that counterinsurgency theories still exist within current operations through several key teachings: the importance of popular buy-in through integrated military and political action and through a sustainable strategy, the oil stain, as well as tactics based on adaptability. These lessons bear witness to our military commitments, so it is essential to capitalise on these experiences in order to maintain contact with our know-how and our history.

Beyond that, several questions remain about the viability of counter-insurgency operations. Can counter-insurgency operations operate in the form of a reduced Western engagement, simply in support of Loyalist forces (the 'light footprint' concept)?¹⁶ ? This also raises questions about the ability of the West, once security is restored, to engage in nation-building and thus about the "exportability " of our model of liberal democracy. In the end, one certainty remains, as with many military operations (and certainly more so for those involving engagements among peoples), counter-insurgency operations cannot be considered as a "light footprint".Counter-insurgency operations do not escape the extreme importance of a well-conducted intelligence operation, as well as its corollary in a populated environment, intercultural training.

9 The European Union's Operation Artemis command in the Democratic Republic of Congo, as well as the British and American contingents in Afghanistan as part of ISAF, have made use of it.

10 Taken from a letter from Marshal Gallieni explaining the oil stain process to Alfred Grandidier, a Malagasy explorer, quoted by Colonel Lyet in: "Gallieni, Joffre", Revue historique de l' arm&e acute;e, 1963/4, p. 91.

11 Sir Gerald Templer, sceptical of the British soldiers' capacity for immersion and openness to inter-culturality, decided to use locals and 'returned' insurgents for the acquisition of human intelligence.

12 Some authors argue, contrary to a commonplace assumption, that the American forces nonetheless carried out a genuine 'nomadisation' work to immerse themselves, particularly in Kapisa. This according to: 'Gaining hearts and minds: historical origin of the concept, current application in Afghanistan', Lieutenant (R) Bertrand Valeyre, Cahiers de la recherche doctrinale, 2010.

13 The British contingent in charge of Helmand Province will thus suffer losses with a higher exposure rate than in Vietnam and the Falklands (one chance in 36 of being killed in operations). Ibid.

14 The Village Stabilization Operations initiative also shows that although attrition is initially higher than "confinement" in FOBs, the immersion of soldiers in the heart of the population enables them to gain their confidence more easily and reduces losses in the long term. Cf . in this regard the article by SGT (R) Hugo Queijo, "Les Village Stability Operations / Afghan Local Police" and the " Transition Strategy" in Afghanistan, Brennus 4.0, CDEC, April 2019, available at www.pensee-militerre.com.

15 "The entire logistics function [...] had to be adapted in order to allow a tool initially designed to support an IATF acting in a single direction to simultaneously support up to three IATFs in three directions" Rémy Hemez and Aline Leboeuf: "Retours sur Sangaris. Entre stabilisation et protection des civils ", Focus stratégique, No. 67, April 2016, p. 19.

16 The average duration of counter-insurgency engagements is fourteen years.