Sylvain Domergue, Associate and Doctor of Geography, teacher at Sciences Po Bordeaux, author of « Geopolitics of maritime spaces » (Armand Colin) and « Geography of the seas and oceans » (Photographic Documentation – CNRS Editions).
Interview organized and conducted by Pierre Verluise, doctor in Geopolitics, founder of Diploweb, he produces Planisphère on RCF Notre Dame. This program was broadcast live on May 5, 2026.
Synthesis by Emilie Bourgoin, a senior student of the Master’s degree in Security and Defense at the University of Ottawa, after a BBA at EDHEC. She is in charge of the weekly monitoring of the news of books, magazines and geopolitical conferences as well as the writing of the summaries of the episodes of the Planisphère show for Diploweb.
As you know, the sea represents 71% of the surface of planet Earth. And most of the products we use have come to us… in containers transported by sea. And yet, we are very unaware of the realities of these spaces on which we depend more every day. The geopolitics of the seas and oceans is asserting itself as an essential field to understand the transformations of the contemporary world and anticipate the conflicts and cooperations of tomorrow. So, what does the geopolitics of maritime spaces teach us? To answer this question, Planisphère is happy to receive Sylvain Domergue. Podcast and written summary.
This program [1] Planisphere, What does the geopolitics of maritime spaces teach us? With S. Domergue, on RCF Notre Dame
Synthesis of this program, Planisphère, What does the geopolitics of maritime spaces teach us? With S. Domergue Written by Emilie Bourgoin for Diploweb.com. Reviewed and validated by S. Domergue
Maritime spaces occupy a central place in contemporary globalization, both for economic exchanges and for strategic and security issues. Yet they remain largely unknown to the general public, despite their crucial importance. Through his analysis, Sylvain Domergue highlights the rise of the sea as a space of dependence, rivalries and geopolitical innovations. He thus proposes to rethink geopolitics from the maritime fact, by insisting on the diversity of actors, threats and ongoing transformations.
The maritimeization of the world: a growing dependence on the oceans
Sylvain Domergue redefines the concept of « maritimization » by going beyond the simple intensification of trade. He insists on a much wider dependence of contemporary societies on maritime spaces.
This dependence is manifested on several levels. First, world trade is mainly based on maritime transport. But beyond that, the oceans play an essential role in data transmission, with about 97% of international communications passing through submarine cables. They are also a major source of resources, whether they are fisheries, energy (oil, gas), genetic (RGM: marine genetic resources) or mineral resources (metals, sand), the latter two being still very little exploited to date.
Thus, the sea appears as a multidimensional strategic space, essential to the functioning of contemporary economies.
A recomposition of power ratios at sea
Maritime spaces are also the scene of a transformation of the balances of power. If some traditional powers such as the United States or France retain a global capacity for action, new actors are emerging.
A transformation of the « grammar of power ».
China is now a major naval power, with a very rapid development of its military capabilities. Other states such as India or Turkey are also strengthening their maritime presence. In addition, powers such as Russia or Japan are experiencing a resurgence in naval activity after periods of relative retreat.
Renewed and hybrid forms of conflict
Maritime spaces are marked by a diversification of forms of violence. Sylvain Domergue stresses that conflict is no longer limited to classic military confrontations, but extends to indirect actions, often difficult to attribute.
Attacks on strategic infrastructure, such as pipelines or submarine cables, illustrate this development. These actions make it possible to weaken an opponent while remaining below the threshold of open war.
Moreover, the dronization of naval conflicts is a major break. The example of the war in Ukraine shows that an actor with limited resources can neutralize a large naval power thanks to drones or remote-controlled devices. This evolution calls into question traditional balances and redefines military capabilities at sea.
The rise of non-state threats and diffuse violence
Beyond the States, maritime spaces are still the scene of activities carried out by non-state actors. Piracy, motivated by economic objectives, remains present in several strategic areas such as the Gulf of Guinea, the Strait of Malacca or the Gulf of Aden.
Other forms of violence exist, more discreet but equally worrying. Sylvain Domergue mentions in particular the working conditions in certain maritime sectors, close to forced labor, as well as the illicit trafficking that exploits the flaws of maritime control.
These phenomena illustrate the complexity of security issues at sea, where economic, criminal and strategic logics coexist.
Environmental issues: a factor of growing tensions
Maritime areas are also at the heart of environmental issues. The overexploitation of fisheries resources, with a significant share of stocks in a situation of overfishing, is a major threat.
Practices such as factory ships or illegal fishing increase these pressures, while making it possible to circumvent regulations. In addition, phenomena such as the exploitation of sand or global warming contribute to the degrade of marine ecosystems.
These dynamics can have indirect security consequences, pushing some populations to turn to illegal activities such as piracy or trafficking.
Fragmented and incomplete maritime governance
The governance of maritime spaces is based on a complex articulation between national, regional and global levels. While progress has been made, particularly with the development of international law of the sea and multilateral institutions, important limits remain.
At the national level, States can only act in their areas of sovereignty, which limits the fight against transnational phenomena. At the global level, the mechanisms exist but suffer from a slow and complex implementation.
The Treaty on the High Seas (BBNJ), which came into force in 2026, is an important step forward, especially in terms of environmental protection. However, it remains largely declarative for the moment and will depend on future implementation mechanisms.
Finally, the regional scale, which has been increasingly valued in recent decades, has multiple interests: reducing the number of actors involved – compared to the global scale – while pooling means and levers of action, in order to fight more effectively against transnational risks and threats (narcotrafficking, major climate risks, maritime crime, etc.). However, the cooperation implemented at this scale still suffers from many governance deficiencies, and very unequal levels of advancement depending on the regions and themes considered.
Conclusion
Sylvain Domergue’s analysis highlights the central role of maritime spaces in contemporary power, security and development dynamics. The sea appears at the same time as a space of dependence, competition and strategic innovation.
However, this centrality is accompanied by major challenges: diversification of threats, fragility of environmental balances and insufficiency of governance mechanisms. In this context, a multiscale and multidimensional approach is necessary to understand and regulate these spaces.
Thus, the geopolitics of the seas and oceans is asserting itself as an essential field to understand the transformations of the contemporary world and to anticipate the conflicts and cooperation of tomorrow.
More:
. Sylvain Domergue, « Geopolitics of maritime spaces » (Armand Colin) and « Geography of the seas and oceans » (Photographic Documentation – CNRS Editions).
. On Diploweb.com, Florian Manet, « Thalassopolitics of drug trafficking, the hidden side of globalization? » and complete book in PDF format on the SEFACIL Foundation website
. On Diploweb.com, Geopolitical file: Seas and oceans at the heart of globalization
. Minarm, Navy Strategic Study Centre
