Following the merger with the CHEAr, armaments became an inseparable part of IHEDN's broader strategic thinking, making the Institute a major meeting point for players in the Defence Technological and Industrial Base (DTIB). «Any strategic reflection must consider the associated resources», explains Étienne Paris:

The return of uninhibited conflict and high-intensity warfare in Eastern Europe means that France, like its partners in the Atlantic Alliance, must prepare for the Major Engagement Hypothesis (MEH). In other words, the scenario in which the operational commitment of the armed forces would be at its maximum. This preparation involves planning not only for the projection of a force abroad as part of a multinational coalition, but also for managing the consequences on national territory.

A major engagement in Eastern Europe would inevitably put a strain on France's vital functions. Health systems, both military and civilian, would be destabilised: heavy demands on health establishments, disruption of logistical flows including health products, organisation of a chain of evacuation of wounded and sick across Europe, etc.

«The scale and complexity of these challenges must be anticipated so that France can guarantee the best level of care for the population in general, and the military in particular,» says General Eric Czerniak, Head of the Operations Division of the French Armed Forces Health Service (SSA), a joint structure under the direct authority of the Armed Forces Chief of Staff.

This reflection must also take into account the fact that a major commitment is first and foremost part of a multinational coalition. The treatment of foreign patients (both military and civilian) in French medical facilities must therefore also be planned.

On the one hand, the concept of «host nation support» requires NATO nations to provide the required support - including medical support - to allied armed forces transiting or staying on their territory. On the other hand, the population movements generated by a conflict are likely to cause an influx of refugees on national territory, and therefore an additional burden on the healthcare system.

The cross-functional nature and the workload of the planning justifies the involvement of all government departments. Strictly military preparation of the healthcare system for the EHF cannot meet the nation's health and resilience challenges. It must therefore be part of an interministerial approach.

This need had already been demonstrated during the Covid-19 crisis. General Czerniak explains the lessons that were learned:

«Although the context is different, this exceptional situation has shown us that a health crisis can have consequences that go beyond the health sphere. In France, the economic and social impact meant that the actions of the various ministries (Health, Economy, Interior, Armed Forces) had to be coordinated. The EMH requires a similar methodology».»

The economy has always been a mainspring of national power. From the industrial revolutions of the 18th century onwards^e In the 21st century, international competition also involves innovation, mastery of technological standards, productivity gains and, ultimately, economic domination.

For the current period, the changeover began in the second half of the 20th century.^e In the 19th century, a new paradigm emerged: that of generalised economic interdependence (or a totally open economy). With the opening up of markets, the unprecedented intensification of the movement of capital, goods, technologies and, to a lesser extent, labour, powers can no longer rely solely on their internal resources. They have to secure global supply chains of raw materials, components, energy, data and skills.

Never before has international trade reached such a volume (+900% since 1980) and value in 2024 (33,000 billion dollars). Trade flows therefore serve the ambitions of economic power.

But the corollary of this development is the emergence of increasingly conflictual relations, confirming what the American essayist Edward Luttwak described in 1990 as the «logic of war in the grammar of trade». States are now pursuing strategic objectives using economic instruments: the United States through tariffs and technological controls, China through its central role in the refining of many critical minerals and in certain industrial chains, Taiwan through its decisive role in advanced semi-conductors, and the Gulf monarchies through their ability to influence energy markets.

Because this interdependence not only produces prosperity, the economy becomes a weapon of conflict when the survival of a national model depends on resources, flows or technologies controlled elsewhere. In other words, the more interdependence there is, the more dependence can become an exploitable weakness.

It was through his monumental work, Théories Stratégiques (published in five volumes between 1929 and 1935), that Castex earned his place in the pantheon of great military thinkers. Often compared to the American Alfred Mahan (1840-1914) or the Prussian Carl von Clausewitz (1780-1831), he went beyond the strictly naval framework to develop a global strategy incorporating innovations that his predecessors had not seen, such as submarines, aviation and the notion of «total war».

At the end of 1996, the great strategist Hervé Coutau-Bégarie, the architect of the re-publication of the «Théories» six decades after their publication, declared at the École Militaire:

«Admiral Castex's influence was great. He was read, and still is, all over the world, particularly in Spanish-speaking countries and in Japan, where the Theories have been translated in their entirety despite their 3000 pages, but also in the United States, throughout the Mediterranean world, in Sweden and even in Soviet Russia, which translated extracts at the height of the Stalinist purges.

Even today, when the US Navy sets out to develop a new manoeuvre-based doctrine, it turns to Admiral Castex for a translation of Volume II of his Theories on strategic manoeuvre.»

In his presentation of the 1996 reprint, Coutau-Bégarie emphasised that this «monumental work goes beyond maritime strategy to encompass general strategy and geopolitics». Castex understood before anyone else that victory did not depend solely on the strength of cannons, but on the synergy between the political, the economic and the military. This global vision is the cornerstone of what we now call national defence.