This change in the nature of the threat at sea and the required responses were discussed by senior naval leaders at the Paris Naval Conference 2025 on 4 February, an event hosted jointly by the French Navy and IFRI (the French international relations institute).
Admiral Nicolas Vaujour, the French Navy’s Chief of Staff, underlined that collective action, including improved information sharing, is integral to finding new ways to tackle the evolving threat. This threat, he said, involves more uninhibited activities – including violence – conducted at sea by various actors.
“We see that in the Red Sea, where a small militia has targeted civilian [shipping] companies, and we have to protect that,” said Adm Vaujour. In this instance, since October 2023 the Yemen-based Ansar Allah (Houthi) rebels have been attacking commercial and naval shipping in the Red Sea/Bab-al-Mandeb/Gulf of Aden corridor.
“We see that in the Baltic, when we are challenged on the seabed, with many cables cut,” Adm Vaujour continued. “We see that also with international regulations being challenged: we see an increasing number of ships becoming ‘ghost fleet’ [vessels] … challenging the way we are organising the world economy.” ‘Ghost fleet’ ships are alleged to be involved in breaking international maritime sanctions on oil exports targeted at certain countries, and have been at the centre of national investigations in the Baltic following several incidents since October 2023 where seabed cables and pipelines have been ruptured, perhaps by ‘ghost fleet’ ships dragging their anchors at speed across the seabed.
“It’s a challenge not only for the shipping companies; it’s a challenge for all the navies,”
Admiral Nicolas Vaujour, Chief of Staff of the French Navy
“Taking into account that the majority of goods travel by ship, that 99% of all global communication goes through fibre-optic cables on the seabed, connecting the continents, and that a lot of the energy infrastructure, especially for Europe, consists of pipelines on land and on the seabed, we are challenged in three of the most crucial areas in the modern global economy at the same time,” said Rear Admiral Oliver Berdal, the Royal Norwegian Navy’s (RNoN’s) Chief of Navy.
The RNoN is enhancing an already well-established relationship with Norway’s civil maritime sector to address threats to shipping and critical underwater infrastructure (CUI). “The challenges we are facing right now are not purely military in nature and they’re not purely civilian in nature. That also means the response and the solution to the challenges cannot be purely military or purely civilian,” said Rear Adm Berdal.
He also highlighted a legal issue, if incidents like damage to seabed cables occur in international waters, outside of any one country’s territorial waters.
If a ‘shadow fleet’ vessel was involved in such an incident in such a location, a nearby country or naval vessel would not be able to act at a national level but would instead need to approach the ship’s flag state. Such approaches can lengthy, and be legally and politically complex. “Changing international law is very difficult and takes time, which means … [currently] having probably limited means to take very decisive action,” said Rear Adm Berdal. “At the same time – as countries, and as allies and partners – we need to show a willingness to do something about it.” “This very quickly becomes a highly political issue. So, how far are we willing to go without necessarily having all the national legal frameworks in [place], because we have not really been tested in this ‘grey zone’ before?” he asked.
“Working more closely with the private sector is the solution, because there’s a lot of assets in the private sector and we fully need to leverage them nationally, but also together,” Rear Adm Berdal concluded.
The threat is impacting the fundamental operation of the global maritime trading system, and the use of the high seas as an open ‘global commons’, Admiral Sir Ben Key, the UK Royal Navy’s First Sea Lord and Chief of the Naval Staff, said.
The task for navies is establishing how to secure this trading system and ‘global commons’ while facing a threat not seen before, Adm Key explained. This threat includes sea denial being generated by organisations with no navy, maritime heritage, or maritime understanding. “That’s where navies need to respond, and countries need to find ways of underpinning that, because if we don’t, then the tradition of almost every navy in the world – to secure trade and economic activity …. – will come under significant threat,” he said.
“Sea denial used to be a military discipline. Today, it’s a discipline carried out by civilian actors; it’s a discipline done by hybrid warfare. So, it’s difficult to manage,” said Rear Admiral Soren Kjeldsen, the Royal Danish Navy’s (RDN’s) Admiral Danish Fleet. “However, to manage it you need to establish a recognised maritime picture. We cannot do that alone anymore. We need to do that with civilian actors, with CUI owners, and with companies operating merchant vessels,” he said. “We have to co-operate with different agencies within our own government, because the responsibilities are shared between different agencies.”
The US Navy’s Vice Admiral Jeffrey Anderson, Commander US 6th Fleet, noted that the combined state/non-state actor threat is exacerbated by the use of hybrid tactics, and is prevalent from the Eastern Mediterranean up into the North Atlantic.
“The key is what can we do about it,” he added. “We have some formal structures in this theatre that we rely on, within NATO. There are also some more informal structures we can rely on as well, like multilateral frameworks.”
“The bottom line is whatever we’re going to do, we have to do it together,” said Vice Adm Anderson.
