Old Ships, Modern Menace: How to Tackle the World’s Shadow Fleets
•January 28, 2026
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Why It Matters
Shadow fleets undermine global trade security, fuel illicit state revenue, and pose severe environmental hazards, demanding coordinated policy action.
Key Takeaways
- •Shadow fleets handle 12% global maritime trade
- •48% of large oil tankers operate covertly
- •US seized seventh shadow tanker on Jan 21, 2026
- •No successful prosecutions of shadow‑ship crews to date
- •Coordinated NATO‑G7 policy needed to curb fleets
Pulse Analysis
The surge of so‑called shadow or ghost fleets reflects a convergence of aging maritime assets and sophisticated deception tactics. Vessels routinely switch off AIS transponders, fly false flags and conduct clandestine ship‑to‑ship transfers, allowing sanctioned oil and illicit cargo to slip through global supply chains. Their dilapidated condition amplifies the risk of spills, as recent incidents in the Baltic and Atlantic seas illustrate, turning these rusting tankers into floating environmental time‑bombs that threaten coastal economies and marine ecosystems.
Beyond commercial concerns, shadow fleets have become a cornerstone of hybrid warfare for states such as Russia, Iran and China. By moving 65‑70% of Russia’s seaborne oil exports and participating in subsea cable sabotage, these vessels provide both revenue and strategic leverage while staying below the threshold of open conflict. The dual‑use nature of the fleets—combining logistics, espionage and potential drone launch platforms—complicates traditional law‑enforcement tools and forces NATO to confront a grey‑zone threat that blurs the line between criminal activity and state‑sponsored aggression.
Policy responses to date—isolated seizures, ad‑hoc sanctions and limited naval interdictions—have proven insufficient. The core challenge lies in fragmented registries, opaque ownership structures and the lack of a unified legal authority to board and prosecute. A viable solution requires a NATO‑G7 task force that integrates maritime intelligence, harmonises sanctions, and pressures insurers and flag states to deny services to covert vessels. Extending cooperation to non‑G7 maritime hubs, especially in the South China Sea, would close critical loopholes and transform the current governance vacuum into a coordinated, enforceable framework capable of curbing the shadow fleet menace.
Old Ships, Modern Menace: How to Tackle the World’s Shadow Fleets
Shadow fleets sit at the centre of maritime hybrid warfare, economic security and environmental risk. Despite this growing recognition, the West lacks the coherence to confront it.
Anna Matilde Bassoli and Emma Isabella Sage – 2026, published by RUSI
The global crackdown on shadow ships continues with the American seizure of a seventh tanker on January 21. This follows the capture of Bella 1 (renamed Marinera) after a weeks‑long pursuit by US and UK forces despite a Russian naval escort. Separately, Europe’s battle against shadow ship cable‑cutting continued, with France and Finland each interdicting a shadow ship within three weeks. The surging attention paid to these vessels has taken an unpredictable path, with their profile rising as they transitioned from implements of sanctions evasion to irregular warfare, and in one case becoming a potential flashpoint for conventional war.
Shadow fleets are not just an adversarial tool, but a threat in their own right. Both American actions against shadow ships leaving Venezuela and European actions against Russian shadow ships are too limited and specific in scope to have a meaningful global impact. Treating shadow fleets as an auxiliary problem has produced auxiliary results; effective policy will require a strategy designed around the specific challenges of this threat.
A Growing Menace
Shadow fleets – also known as dark or ghost fleets – operate outside the rules that govern most maritime traffic. They fly false flags, spoof tracking signals, falsify manifests and conduct ship‑to‑ship transfers to conceal the origins of sanctioned or illicit cargo. Their number is still growing despite countermeasures, and they will continue to empower malign actors until the West evolves from sporadic enforcement to a coherent, coordinated policy agenda.
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Over 12 % of global maritime commerce and at least 48 % of the world’s large commercial oil tankers run on shadow fleets.
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The average shadow ship is at least 20 years old, and their dilapidated condition poses a serious risk of environmental catastrophe worldwide, with Russia’s shadow fleet spilling oil in the Northern Atlantic, Mediterranean, and Indian Ocean.
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Ramshackle shadow ships also endanger safety of navigation wherever they operate, as when the oil tanker Eventin broke down in the Baltic Sea, forcing Germany to tow it to safety.
Maritime Hybrid Warfare on the Rise
A classic grey‑zone threat, shadow‑fleet activity remains below the threshold of armed conflict, yet beyond the effective reach of law enforcement. Shadow fleets offer economic gains and plausible deniability, which has driven their expanding role in conflict. Russia, Iran, Venezuela and China have turned shadow fleets into tools of statecraft and even spy craft, with the potential for much greater harm to come.
Russia’s shadow fleet has become a key pillar of its financial ability to withstand sanctions and sustain the war effort in Ukraine. An estimated 1,300 vessels as of 2025 have carried 65‑70 % of Russia’s seaborne oil exports since the beginning of the war. Proof that these ships served a dual purpose came in the series of subsea cable sabotages in the Baltic Sea, responsible for 11 confirmed damages in 15 months until the beginning of NATO’s Operation Baltic Sentry. Russia may have adopted new tactics, re‑tasking the shadow ships from physical infrastructure damage to espionage, with potential uses as a launch platform for drones or for GPS jamming.
“Beyond cutting shadow fleets out of Western shipping and maritime insurance markets, a global effort to interdict shadow ships must replace isolated seizures.”
The issue is not limited to Russia: China has been a key partner in the Baltic Sea sabotage campaign and has also used shadow ships to damage subsea cables around Taiwan. China’s long history of covert maritime practices includes a large illegal‑fishing fleet that has diversified toward illicit oil transportation in collaboration with Russia, simultaneously importing discounted Russian oil and undermining Western security.
Similarly, Iran’s shadow fleet has been central to funding the Islamic Revolutionary Guard Corps (IRGC) and its foreign terrorist affiliates. Iran’s strategic position astride chokepoints such as the Strait of Hormuz heightens the risk that these vessels could be tasked with broader coercive or disruptive missions.
Roadblocks All the Way Down
Although shadow fleets are a major security risk, any serious attempt to curtail them could shock the fragile web of global trade. As shadow ships grew from a nuisance into a pressing security threat, the absence of a coherent response from Western actors can be explained by economic concerns and the operational difficulties associated with shadow ships.
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Finding the ships – AIS transponders are routinely switched off or spoofed, registries are fragmented, and beneficial ownership is obscured by offshore shell structures outside NATO jurisdiction. OSINT investigators and maritime‑tracking platforms have stepped in where governments lag, but this ad‑hoc architecture is neither comprehensive nor authoritative.
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Boarding and detaining – When an incident occurs, it is often unclear whether it constitutes an accident, criminal negligence, or state‑sponsored aggression, which determines the responsible authority. The EU has no coast guard and NATO has no legal authority to board commercial vessels. Individual states act inconsistently, bound by domestic law, divergent risk appetites and limited naval resources.
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Prosecution – Which entity prosecutes the crime, under which law, and in which court? A Finnish court recently dismissed a case against a shadow‑ship crew with no further action planned, highlighting the complete inadequacy of current legal architectures even in clear cases of sabotage. To date, there has not been a single successful shadow‑ship prosecution.
These gaps define a governance vacuum in a domain that once symbolised the expansion of the rules‑based global order. Until the West acts to change this broken system, the world’s oceans will remain the largest ungoverned space on earth – and rusting tankers, the most dangerous symptom of that neglect.
Beyond Sanctions and Seizure
The US and EU have employed both regulatory and kinetic tactics against shadow fleets, but neither has proven to be a panacea. While regulation alone has clearly failed, kinetic efforts are outmatched by the scope of the threat.
The seizure of the Skipper (sanctioned in 2022 for smuggling Iranian oil under the name Adisa) illustrates the difficulty: it took three years for US forces to stop the outlaw ship, and it likely never would have happened without the political showdown between the US and Venezuela. Likewise, while subsea‑infrastructure sabotage has dropped significantly under NATO’s Operation Baltic Sentry, Russian shadow ships have not ceased to cut cables, move Russian oil or conduct espionage.
Sanctions and isolated seizures are partial remedies. Each sanction imposed on an individual ship drives further opacity – new flags, new shell companies, new routes – perpetuating a cycle in which regulation is always one step behind. Even blockades leave the corporate, financial and legal networks of shadow fleets intact. Beyond enforcement challenges and escalation risks, seizures also pose a resource problem: the hunt for the Marinera/Bella 1 demonstrated the scope of the operation required to capture a ship which refuses to be boarded.
As the greatest dual‑use challenge to Western allies, shadow ships necessitate a multi‑pronged approach targeting both the fleets themselves and the networks that facilitate their existence. First, NATO states must address Western enablers. While Greece’s tankers are now playing a diminished role in the Russian oil trade, the Greek shipping sector still facilitated the growth of Russia’s shadow fleet in spite of EU sanctions. Most shadow ships have started providing evidence of insurance when challenged, often from Western insurers such as Maritime Mutual, which was raided by New Zealand police after allegedly providing cover for dark vessels carrying Iranian and Russian oil. Shadow ships therefore require a broad campaign of law‑fare, far beyond the remit of overwhelmed sanctions offices.
Beyond cutting shadow fleets out of Western shipping and maritime insurance markets, a global effort to interdict shadow ships must replace isolated seizures. Initiatives like the G7 Shadow Fleet Task Force are a positive step, but they overlook the key role of non‑G7 countries in enabling or combating shadow fleets. A more meaningful step would involve countries in the South China Sea, the world’s busiest waterway, where shadow ships already imperil maritime traffic.
The West now faces the consequences of deferred decisions. Until the gaps exploited by shadow fleets are closed, the seas will remain the least‑governed, most‑contested domain.
© Anna Matilde Bassoli and Emma Isabella Sage, 2026, published by RUSI with permission of the authors.
The views expressed in this Commentary are the authors’, and do not represent those of RUSI or any other institution.
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