1. Introduction
Debates on the law governing the nationality of ships have traditionally centred on the ability of flag States to exercise effective control over ships flying their flag, particularly regarding flags of convenience (FOCs)—ship registries imposing fewer regulatory requirements that are open to foreign-owned ships. However, concerns that the distance between open registries and foreign-owned ships hampered their ability to exercise effective control have largely subsided.Footnote 1 Today, more than 70 per cent of the global merchant fleet is registered in FOCs,Footnote 2 many of which are considered responsible flag States.Footnote 3
This article proposes that ship nationality debates should turn to the willingness, rather than the ability, of flag States to exercise effective control over their vessels. Illustrating this shift, this article focuses on the ‘shadow fleet’ phenomenon which has arisen in the last three years, following the introduction of the price cap on Russian crude oil at the end of 2022, as a threat to the public order at sea. Its central argument is that a flag State may not assert exclusive jurisdiction over its ships vis-à-vis third States if it is unwilling to effectively control them—particularly if it consciously shelters the dark fleet.
‘Dark fleet’ or ‘shadow fleet’ refers to aging, decrepit vessels often carrying sanctioned cargo—mainly oil—primarily from Iran, Russia and Venezuela. Following the International Maritime Organization (IMO), dark ships may be understood as those ‘engaged in illegal operations for the purposes of circumventing sanctions, evading compliance with safety or environmental regulations, avoiding insurance costs or engaging in other illegal activities’.Footnote 4 Allianz estimates that the shadow fleet comprises approximately 600 tankers, roughly 17 per cent of the overall global tanker fleet, and that these have been involved in more than 50 incidents.Footnote 5 These vessels typically avoid entering foreign internal waters to evade coastal State control but nonetheless pose threats to navigational safety and to the environment, including through unregulated ship-to-ship oil transfers.Footnote 6
While some dark ships fly traditional FOCs, others have turned to less-established flags whose registries have seen sudden surges,Footnote 7 especially as some major FOCs have deregistered or refused to register dark ships at the request of sanctioning States.Footnote 8 Some such ships fly ‘false flags’, meaning the registration or the registry itself is fraudulent, thus the purported flag State never granted its nationality to the ship. Falsely flagged ships are stateless, and any State may enforce its laws against them.Footnote 9
Other dark ships are validly registered, and their flag States enjoy, a priori, exclusive jurisdiction, together with navigational rights according to the maritime zone in which they are located.Footnote 10 For these ships, the Lloyd’s List—a preeminent journal dedicated to shipping news—has coined the term ‘flags of deceit’ (FODs), designating flag States whose ‘conscious intent is to enable the operation of [the] dark fleet’,Footnote 11 which might include, or might have included in the past, flag States like Gabon, Comoros, Cameroon and the Cook Islands.Footnote 12 In 2024, the European Parliament passed a Resolution that referred to recalcitrant flag States as ‘aiding the Russian “shadow fleet”’.Footnote 13
So far, responses to the shadow fleet have been limited, and some bolder proposed measures are hindered by FODs’ navigational rights and exclusive jurisdiction over their ships. For instance, Denmark has explored ways to prevent the shadow fleet from carrying Russian oil through the Baltic Sea,Footnote 14 and the abovementioned European Parliament Resolution urged the adoption of measures such as the denial of shadow fleet access to ‘European waters’ by coastal States, inspection of dark ships for IMO compliance ‘including at sea’, restrictions on the shadow fleet’s ‘use of the English Channel’ and requiring proof of insurance and compliance with safety standards in international straits.Footnote 15
However, unless a ship is stateless,Footnote 16 international law affords coastal States few enforcement options beyond their internal waters. This is because the flag State’s exclusive jurisdiction still seems an impenetrable barrier, providing navigational rights in foreign territorial seas, EEZs and on the high seas, even where flag States deliberately enable the operation of the dark fleet.Footnote 17
It is against this backdrop that this article argues that FODs may not assert exclusive jurisdiction over their ships vis-à-vis third States because they are unwilling to effectively control their ships. This argument proceeds in three stages.
First, in Section 2 it situates the shadow fleet as a new facet within the law governing the nationality of ships. The debate on FOCs, which has shaped discussions in this field, has traditionally focused on the ability of flag States to exercise effective control over foreign-owned ships flying their flag, notably in the case of small developing States like Liberia. The main problem with the inability argument has been the difficulty in conclusively proving that a particular flag State is unable to implement its duties. Indeed, the example of the Marshall Islands shows that bona fide FOCs are able to exercise effective control over their vessels—even if smaller in size and resources.Footnote 18 Questioning their ability, some States and scholars proposed limitations on States’ right to grant their nationality to foreign-owned ships, including through the cryptic concept of the ‘genuine link’ between a ship and the flag State.Footnote 19 However, this was to no avail, as FOCs have become an important part of the shipping industry.Footnote 20 In contrast, the debate on FODs questions the willingness of the flag State to exercise effective control over ships flying its flag, not necessary its ability to do so. The argument suggests that FODs are actually unwilling to implement their duties.
Second, this article examines in Section 3 the flag State’s exclusive jurisdiction, which is a corollary of ship nationality. It is advanced that this exclusive jurisdiction has a dual-purpose nature. On the one hand, it enables the flag State to exercise freedom of navigation and other navigational rights through ships flying its flags. On the other, it allocates to that State the responsibility to control its ships to maintain the ‘public order at sea’—a doctrinal concept that has evolved to encompass maritime security, navigational safety and environmental protection.Footnote 21
Finally, building on this theory of the dual-purpose nature, in Section 4 it is posited that, if the flag State is demonstrably unwilling to assume this responsibility, it may not assert its exclusive jurisdiction vis-à-vis third States—meaning that third States have the right to refuse to recognise FODs. Flag non-recognition does not entail challenging the international validity of a ship’s registration. The ship retains its nationality and right to fly the flag concerned—rights usually based on registration, particularly in commercial shipping. As this distinction is drawn, it becomes necessary to revisit the M/V “Saiga” (No 2) (Saiga (No 2)) judgment by the International Tribunal for the Law of the Sea (ITLOS, Tribunal), which appears to conflate challenges to the validity of a ship’s registration and the decision whether to recognise a foreign flag.Footnote 22
Considering the lawfulness of such a decision, it is also important to examine how flag non-recognition can occur in practice. The FOD concept is legally useful because it describes a flag State unwilling to implement its duties and, thus, be subject to flag non-recognition. However, in reality, defining a flag State as such might not be a clear-cut assessment, and establishing contact with the flag State might still be necessary.
2. Ship nationality reconsidered in response to the shadow fleet
Debates on the nationality of ships are not new. International legal issues concerning ship nationality first arose in the 1890s, when it was widely accepted that States were free to fix the conditions for granting their nationality to ships.Footnote 23 As shipowners began registering their ships abroad more frequently, the Institut de Droit International (IDI) identified emerging legal issues concerning the applicable law in private relations and the characterisation of ships as enemy merchant vessels in wartime.Footnote 24 To address these difficulties, the IDI proposed unifying registration requirements across States to the effect that ships flying the flag of a State should be owned and controlled by a national of that State.Footnote 25 This proposal had no immediate impact on the law governing the nationality of ships.
After the Second World War, small States with open registries, such as Panama, Liberia and Honduras, grew in popularity as FOCs. Their lower taxes and lighter regulatory regimes appealed to shipowners but provoked concern, particularly from trade unions, that such registries compromised the effective control of such vessels, especially in relation to navigational safety and labour conditions.Footnote 26
Having started its work on the law of the sea in 1949, the United Nations (UN) International Law Commission (ILC) included this issue in its 1956 Articles concerning the Law of the Sea (1956 Articles).Footnote 27 Though the ILC acknowledged that States were free to fix the conditions for granting their nationality to ships, it introduced the requirement of a ‘genuine link’ between a ship and the flag State, intended to ensure the effective exercise of jurisdiction and control.Footnote 28 This requirement was carried into the Convention on the High Seas (HSC) in Article 5Footnote 29 and later into the UN Convention on the Law of the Sea (UNCLOS) in Article 91(1), which provides that ‘there must exist a genuine link’.Footnote 30
The difficulty was that ‘genuine link’ was left undefined, regarding both its meaning and the consequences following its non-fulfilment. Following the IDI, a common attempt to define it required that a majority of a vessel’s beneficial ownership should rest with entities domiciled in the flag State.Footnote 31 The underlying assumption was that, without fulfilling this condition, the flag State would be unable to perform its obligation to exercise effective control. However, State practice on registration requirements proved so diverse that the ILC preferred to leave it undefined.Footnote 32 The 1956 Articles did mention that this requirement was ‘for the purposes of recognition of the national character of the ship by other States’.Footnote 33 However, this latter excerpt was dropped in the 1958 UN Conference on the Law of the Sea, which adopted the HSC.Footnote 34
In Saiga (No 2), ITLOS ruled out the ‘genuine link’ requirement as establishing criteria by which to challenge the validity of registration.Footnote 35 In that case, Guinea objected to the admissibility of the claim brought by Saint Vincent and the Grenadines (SVG) because ‘Guinea [was] not bound to recognise the Vincentian nationality of the M/V Saiga [in respect of which the case was brought] in the absence of a genuine link between this vessel and the applicant’.Footnote 36 Guinea argued that there was no genuine link because SVG did not exercise jurisdiction over the M/V Saiga’s shipowner or operator and, therefore, could not fulfil its flag State duties.Footnote 37
ITLOS rejected this objection, holding that Article 91 UNCLOS retained the genuine link requirement only to secure effective implementation of flag State duties,Footnote 38 not to set criteria by which other States could challenge registration. ITLOS remarked that Article 5 HSCFootnote 39 had dropped the ILC’s proposed wording tying the genuine link requirement to recognition of nationality by other States and treated Article 94(6) UNCLOS,Footnote 40 which covers reporting suspected ineffective control to the flag State, as the sole remedy for such control.Footnote 41
A contrary ruling could have imposed grave consequences on the shipping industry, with over 70 per cent of the global merchant fleet in dead weight tons registered in open registries.Footnote 42 It would also have been conceptually unsound: a flag State’s ability to implement its duties is not necessarily indicated by the links between that State and the shipowner or operator. Liberia and the Marshall Islands, for example, are respected open registries despite their limited domestic resources.Footnote 43
This is partially because there is no definition for what ‘ability’ should look like. 70 years ago, wide consular reach, maritime ports and naval resources were often seen as essential for effective control.Footnote 44 In today’s hyperconnected world, responsible ship registries may rely, for instance, on a few offices in global hubs, reputable classification societies (non-governmental entities that periodically inspect ships’ compliance with, inter alia, international maritime regulations), cooperation with other States and in multilateral settings, and the power to simply deregister substandard ships. Properly managed, these mechanisms can ensure effective control even of foreign-owned fleets, and small States may establish registries for revenue while maintaining good reputations. The focus on ability, therefore, has become less convincing.
The debate should instead turn to the willingness of flag States to exercise effective control. The challenge then becomes determining how much willingness is enough and how it can be evidenced. Here, the Lloyd’s List description of FODs considered in Section 1 is helpful, since it denotes a flag State consciously intending to enable the operation of the dark fleet. In this case, conceptually, there is clear flag State unwillingness to effectively control its ships threatening the public order at sea—though the evidence issue remains and is addressed in Section 4. This can be contrasted with bad FOCs or ‘flags of non-compliance’, the latter being more traditionally used in the fisheries context. These concepts are more neutral, generally used to describe careless flag States, and the present author makes no conceptual claim about their willingness to exercise effective control over their ships.
The role of private companies adds to this dynamic. While firms have successfully managed responsible registries, such as Liberia and the Marshall Islands, their involvement in the shadow fleet has been prominent.Footnote 45 The proliferation of such registries reflects the business opportunities created when major flags deregister dark ships.Footnote 46 Over the last three years, dark ships have frequently been registered en masse in certain registries, which is impossible to miss and places the flag State concerned under heightened scrutiny.Footnote 47 In this perspective, registries attracting dark ships are not merely careless: to a considerable extent, their operation has deliberately revolved around the shadow fleet.
The Gabonese registry provides a striking illustration. In 2018, it authorised UAE-based Intershipping Services to operate its registries.Footnote 48 By 2024, the Gabonese registry had become the fastest-growing registry by tonnage because of the dark fleet.Footnote 49 Despite intense scrutiny, including the European Union (EU) and the United Kingdom (UK) having sanctioned Intershipping in July 2025,Footnote 50 their operation appears unchanged at the time of writing. By contrast, Comoros, also linked to the shadow fleet, withdrew authority from private operators, with the government centralising ‘the issuance of all certificates’.Footnote 51
While one might argue that poorly performing FOCs are also unwilling to exercise effective control, the shadow fleet phenomenon takes unwillingness to a different level. These registries are not just failing to meet international standards; they are enabling a fleet that openly undermines the rules-based maritime order. This raises legal questions that cannot be adequately addressed by Saiga (No 2) or by the traditional focus on ability. To resolve these questions, it is necessary to revisit the rationale for conferring nationality on ships and the corresponding allocation of exclusive jurisdiction to the flag State.
3. The nationality of ships and the maintenance of the public order at sea
Since the high seas are not subject to appropriation by any State,Footnote 52 the concept of flag State exclusive jurisdiction, as a corollary of ship nationality, was established early as means of maintaining the public order at sea.Footnote 53 Initially, this enabled both the flag State’s freedom of navigation and a guarantee to other States that the State in question’s ships are not outlaws.Footnote 54 This guarantee is today enshrined in Article 94(1) UNCLOS, requiring States to effectively exercise their jurisdiction and control over their ships,Footnote 55 for example, by addressing wrongs committed on board their ships.
Linking this obligation to nationality requirements under international law, including in the form of the genuine link requirement as a registration condition, was an innovative move in the 1950s by the ILC’s Special Rapporteur François.Footnote 56 At the 1958 Conference on the Law of the Sea (1958 Conference), Professor Gilbert Gidel explained:
a clear distinction had to be drawn between the criteria which a State could adopt for the grant of its nationality and the result which those criteria must guarantee. The criteria should be determined by the State at its own discretion … but the final result must in all cases be the same: the effective exercise of control over the ship by the flag State.Footnote 57
This understanding was widely shared. For example, Westlake stated that ‘with such conditions [for registration, like nationality of shipowners] international law has no concern’, but he underscored that ‘it suffices that, for whatever reasons, a state accepts the authority and responsibility which result from the ship’s nationality’.Footnote 58
Focusing on the ‘control’ obligation amid the debate on FOCs, Meyers drew a parallel between flag State jurisdiction and territorial sovereignty,Footnote 59 citing Arbitrator Max Huber’s reasoning in the Island of Palmas award: ‘Territorial sovereignty … involves the exclusive right to display the activities of a State. This right has as corollary a duty: The obligation to protect within the territory the rights of other States’.Footnote 60 Similarly, Meyers observed that the exclusive jurisdiction of the flag State has, as a corollary, the duty to exercise effective control over ships flying its flag to maintain the public order at sea.Footnote 61
The underlying rationale is clear: if a State wishes to preclude third States from exercising jurisdiction, whether on land or at sea, it must protect the rights of those States within its exclusive jurisdiction. A State that is unable or unwilling to protect these rights cannot claim the right to preclude third States from protecting their own rights.Footnote 62 This rationale is much more powerful at sea than on land, because the former is shared whereas the latter is under a State’s territorial sovereignty.
This imperfect, yet pertinent, analogy between territorial sovereignty and flag State jurisdiction was overlooked by the ILC. Instead, François suggested comparing the nationality of ships to that of individuals,Footnote 63 which is not a suitable comparison. The issues surrounding the nationality of individuals at that time, such as dual nationality (positive conflicts of domestic nationality laws) and the risk of statelessness (negative conflicts), do not present the same challenges in the law of the sea.
More importantly, ships are not ‘nationals’ of a State in the way that legal and natural persons are; they are considered property and lack legal personality.Footnote 64 This distinction has been underscored by numerous scholars, notably Meyers, who advocated for replacing ‘nationality’ with ‘allocation’.Footnote 65 This term more accurately reflects how jurisdiction is assigned to the flag State, enabling it to exercise freedom of navigation and control over its ships. The law of the sea allocates authority to States at sea bearing in mind, inter alia, spatial considerations.
In this regard, the high seas require a special legal fiction: the binomial of ship nationality and the flag State’s exclusive jurisdiction over that ship. Before the 1950s and by a scholarly minority, this legal fiction was explained through the ‘floating territory’ theory, according to which ships were considered part of the flag State’s territory. The better view is that the flag State’s exclusive jurisdiction over its vessels need not be justified by this theory;Footnote 66 international law simply allocates (extraterritorial) jurisdiction to the flag State over its vessels. Nevertheless, this theory is insightful because it reveals the raison d’être of the nationality of ships, the allocation of authority, which is distinct from the abovementioned legal issues related to the nationality of individuals.
Given this context, the genuine link requirement, as later understood by ITLOS (the means and willingness ‘to secure more effective implementation of the duties of the flag State’Footnote 67), is ‘as old as the concept of “the nationality of ships” … for without such a requirement the latter concept is [a useless] fiction and public order at sea is impossible’.Footnote 68 This reveals the effective control supposedly secured by the genuine link not as a condition for registration but as the very raison d’être behind assigning ships to the authority of flag States.
Accordingly, just as a State cannot register a ship already possessing the nationality of another State—for the public order at sea would be impossible—Boczek and Dahm correctly argue that States should not grant their nationality to a ship if there are reasonable grounds to suspect that the ship will be used for purposes which violate international law.Footnote 69 From this perspective, the content of flag State responsibility is dictated by the evolving conceptions of the public order at sea insofar as its ships are concerned in view of the applicable international law.
Historically, maintaining the public order at sea primarily concerned the control of piracy and other forms of criminality.Footnote 70 The advent of steamships amidst the industrial revolution in the nineteenth century significantly increased maritime traffic, raising concerns about the safety of navigation and human life at sea. As early as 1924, Dupuis noted that the greatest threat to navigation was the danger of collision, not piracy.Footnote 71
The popularisation of FOCs shifted attention to the labour conditions of seafarers, which are closely linked to navigational safety. Labour laws in FOC States could not match the conditions or wage levels of traditional maritime States, like the UK.Footnote 72 Nonetheless, at the same time this provoked a campaign against FOCs by trade unions,Footnote 73 and the International Labour Organization (ILO) adopted a number of instruments concerning seafarers’ labour rights.Footnote 74 Later, the IMO took a similar approach—not opposing FOCs directly but increasing their responsibilities and improving enforcement mechanisms, such as port State control.
At the same time, the ILC avoided limiting itself to the flag State’s obligation to prevent and repress crimes committed on its vessels, also stipulating obligations relating to ‘safety at sea’.Footnote 75 Since the Titanic incident in 1912, there had been a preoccupation among States and in the shipping industry with unifying the ‘maritime rules of the road’, including the use of signals, maintenance of communication and the prevention of collisions.Footnote 76 Against this background, the concern with FOCs spurred the development in the ILC of what is now known in UNCLOS as rules of reference to generally accepted international rules and standards,Footnote 77 a prime example of which is Article 94(5) UNCLOS. Under this provision, flag States shall conform to such rules and standards as necessary to ensure safety at sea.Footnote 78
The following decades witnessed the burgeoning of international maritime regulations, covering not only the safety of navigation and labour standards but also environmental protection, maritime and port security, seafarer training and ship management. Most of these rules, standards and practices have become an integral part of UNCLOS, going beyond the duties of the flag State in Article 94, which mostly relate to navigational safety.Footnote 79 For instance, Article 217 on the flag State’s enforcement jurisdiction and obligations over vessel-born pollution was crafted as ‘part of the response to the long-standing criticisms of the regime of exclusive flag-State jurisdiction, particularly with regard to lax enforcement by so-called “flags of convenience” States’.Footnote 80
While UNCLOS continues to address traditional criminality concerns (for example, in Articles 99, 100, 108, 109, 110 and 114),Footnote 81 the fundamental role of the flag State in maintaining the public order at sea today is to observe international maritime regulations, as confirmed by ITLOS in M/V Virginia G. Footnote 82 Thus, given the centrality of international maritime regulations in the contemporary public order at sea, although ‘sanctions evaders’ have previously exploited FOCs,Footnote 83 the case of the Russian (and Iranian and Venezuelan) shadow fleet is particularly alarming, not least because it is largely composed of tankers—massive floating environmental risks—accounting for approximately 17 per cent of the global tanker fleet.Footnote 84 Indeed, the shadow fleet’s violation of several international maritime instruments was set out in detail by the IMO Assembly in Resolution A.1192(3).Footnote 85
In this connection, one must underscore that sanctions from the EU, UK or United States (US) on a ship, its owner or operator, do not necessarily mean that a ship will be considered a dark ship as defined in Resolution A.1192(3). Whilst sanctions are recognised as a factor leading to the creation of shadow fleets, they are not the law of the sea’s immediate concern. Instead, its immediate concern lies in the role of flag States allegedly sheltering tankers belonging to the shadow fleet.
As this section has shown, when a State grants its flag to ships, it must accept and take responsibility for them, particularly as their activities impact the public order at sea and the rights of third States. However, what happens if the flag State shirks this responsibility? Can third States only resort to naming-and-shaming or can they go beyond that?
4. Flag non-recognition as a response to the flag State’s unwillingness to exercise effective jurisdiction and control
This article argues is that flag non-recognition may be a lawful alternative if factual evidence clearly demonstrates that the flag State is a FOD, thus unwilling to control its ships to maintain the public order at sea
As noted in Section 2, in Saiga (No 2), ITLOS examined ‘whether the absence of a genuine link between a flag State and a ship entitles another State to refuse to recognise the nationality of the ship’.Footnote 86 The Tribunal stated that Article 91(1) UNCLOS did not provide an answer,Footnote 87 only requiring that ‘there must exist a genuine link’. The Tribunal then referenced Article 29 of the 1956 Articles, which stipulated that ‘[n]evertheless, for the purposes of recognition of the national character of the ship by other States, there must exist a genuine link between the State and the ship’.Footnote 88 Significantly, in the Tribunal’s view, the HSC did not include the first clause of Article 29 (‘nevertheless … by other States’) in Article 5(1)—a choice replicated in Article 91(1) UNCLOS.Footnote 89
Consequently, an a contrario interpretation suggests that while the genuine link requirement was preserved, ‘the proposal that the existence of a genuine link should be a basis for the recognition of nationality was not adopted’.Footnote 90 Supporting this view, ITLOS interpreted Article 94(6) UNCLOS to mean that, in cases where the flag State exercises ineffective control, the only lawful action available to third States is to report the matter to the flag State.Footnote 91
The Tribunal concluded that the genuine link requirement did not ‘establish criteria by reference to which the validity of the registration of ships in a flag State may be challenged by other States’ and that ‘there is no legal basis for the claim of Guinea that it can refuse to recognize the right of the Saiga to fly the flag of Saint Vincent and the Grenadines on the ground that there was no genuine link’.Footnote 92
These findings merit careful consideration for two key reasons. First, ITLOS seems to conflate two distinct concepts: flag non-recognition and the challenge to the international validity of a ship’s registration. Second, the drafting history of Article 5 HSC suggests that its a contrario interpretation is by no means necessary.
Regarding the first reason, the right to refuse recognition pertains to the conclusiveness of States’ unilateral acts vis-à-vis other States. It can be equated to denying the flag State’s exclusive jurisdiction. It is not a challenge to the international validity of the registration nor to the usually consequent grants of nationality and of the right to fly a State’s flag, all of which are mentioned in Article 91(1) UNCLOS.Footnote 93 In the shadow fleet context, a closer example of invalid registration is that of false flags, for they lack the flag State’s intention to register and grant its nationality to a ship. In these cases, the (false) registrations are null and void, regardless of other States’ non-recognition.
This conflation stems in part from the ILC’s own approach, which advanced the genuine link as a condition for ship registration while linking its non-fulfilment to the faculty of other States to refuse recognition of a ship’s nationality. As noted in Section 3, this represented an innovation: the law of the sea had never previously imposed substantive conditions on registration and, in Fitzmaurice’s words, ‘the correct principle for the recognition of nationality was that of effective control’.Footnote 94
The genuine link, as a registration condition, was thus conceived of as a practical expedient for addressing the more fundamental question of effective control.Footnote 95 Yet when defined in terms of the nationality of shipowners or operators, it proved an unreliable indicator of whether effective control actually existed. With the notion of genuine link as a means of securing effective control left undefined, and setting it aside, if a flag State is manifestly unwilling to exercise such control, it can be reasonably assumed that there is no effective control. There is no need to assess whether a genuine link exists, whatever its meaning is. If it is unwilling, the flag State may not assert its exclusive jurisdiction vis-à-vis third States.
Important historical precedents supporting Fitzmaurice’s perspective include an early example from Great Britain, which in 1826 issued an Order in Council authorising the seizing of Greek-flagged armed merchant vessels due to Greece’s lack of effective control over its merchant fleet. The Order stated that ‘His Majesty has in vain applied for the prevention of these outrages to the Persons exercising the powers of Government in Greece, who, however willing, are unable to effectually repress such excesses’.Footnote 96
Another illustrative case is provided by Switzerland. For a long time, Switzerland neither wanted to establish a ship register nor would other States recognise it. In 1854, for example, France declared that it did not recognise the Swiss right to have a maritime flag because its geographical situation did not allow it to control nor to protect its ships.Footnote 97 Eventually, it was understood that, although landlocked, Switzerland was capable of controlling seagoing vessels and, in 1919, landlocked States’ flags were recognised.Footnote 98
A more circumstantiated explanation was offered by Riphagen at the 1958 Conference: ‘The rule that ships on the high seas in general had immunity from the jurisdiction of any state other than the flag state could be justified only by the effective jurisdiction of the flag state over those ships’.Footnote 99 Therefore, emphasising the dual purpose of the nationality of ships, mere registration does not ensure perpetual flag State exclusive jurisdiction to be recognised by other States. For the flag State’s exclusive jurisdiction to be asserted vis-à-vis third States, a ship must bear its nationality and be under its effective control—or, at least, it must be not so obviously outside the flag State’s effective control.
If this were not the case, the nationality of a ship would be a nearly useless fiction. Thus, although a flag State’s granting of its nationality to ships might be perfected and internationally valid, third States have the right to deny the flag State’s exclusive jurisdiction in the face of the lack of effective control over its ships, especially when protecting their own legal interests.Footnote 100
This understanding was affirmed in the first judicial decision addressing the consequences of the inexistence of genuine link, handed down by the US Court of Appeals of the Second Circuit in the 1962 Empresa Hondurena de Vapores, SA v Mc Leod case.Footnote 101 This case is not the only instance where this understanding has been affirmed. Although traditional FOC States like Liberia and Panama have contested the notion of a genuine link based on shipowners’ nationality as a registration condition, they have consistently presented themselves as responsible flag States. Liberia’s statement before the International Court of Justice in 1960 underscored this point:
There is, however, one other aspect of the Nottebohm case to which reference has been made—namely, those parts of the Judgment which relate to the effects in the international sphere of unilateral acts by States … This is a fundamental axiom of international law … But the real objection to unilateral acts does not apply here. This is not a situation in which a State by its unilateral act seeks to acquire benefits without obligations. Membership of the Maritime Safety Committee … is an assumption of responsibility; it is a necessary discharge of duty owed by a State which is responsible for vessels—owed by that State not only to the world generally, but particularly to the men who sail on those vessels and whose lives are at stake.Footnote 102
Today, major FOCs, including the Marshall Islands and Liberia, appear to uphold this general stance to differentiate themselves from FODs.Footnote 103
The second reason why ITLOS’ findings on flag non-recognition merit careful consideration is because the a contrario interpretation at the basis of ITLOS’ judgment is tenuous. The reference to ‘[n]evertheless … by other States’ had been retained by a significant majority in the Second Committee of the 1958 Conference but was deleted in the Plenary two weeks later. Arguably, its deletion was not due to States’ belief that non-recognition was unavailable in cases of lack of effective control. El Salvador proposed deleting this part because it believed that ‘although the Conference was entitled to lay down certain general conditions governing the grant of nationality to ships … the words “Nevertheless …” … seemed to offend against the principle of sovereignty’.Footnote 104 No other delegation commented on the provision in the Plenary.Footnote 105 El Salvador’s argument suggests a concern with conditions the non-fulfilment of which could compromise the international validity of a ship’s registration. This was a cautious decision to preserve FOCs, but it did not mean a rejection of non-recognition in cases of ineffective control.
ITLOS also cited Article 94(6) UNCLOS to hold that ‘nothing in article 94 [permits] a State which discovers evidence indicating the absence of proper jurisdiction and control by a flag state over a ship to refuse to recognize the right of the ship to fly the flag of the flag State’.Footnote 106 This is correct: under Article 94(6), after the flag State receives a report, it must investigate the matter and, if necessary, take the appropriate measures. But it is also true that nothing in this provision nor in its history rules out other States’ right of non-recognition in case of ineffective control, as demonstrated, for example, by reiterated non-compliance with Article 94(6) itself. Sponsoring this provision in UNCLOS, France noted that its addition did not innovate the ‘principles and provisions of the HSC’ on the matter and that it was aimed at stating more precisely ‘the obligations of the flag State since the relevant articles of the [HSC] were incomplete’.Footnote 107
Theoretically, therefore, it is difficult to assert that non-recognition of a foreign flag is legally impossible. The practical challenge is in providing conclusive evidence that a flag State is unwilling to exercise effective jurisdiction and control over its ships. Although the concept of FOD is helpful, establishing that a flag State is unwilling to effectively control its vessels might be not as clear-cut in practice.
Before deciding not to recognise a foreign flag and exercising enforcement jurisdiction over a ship flying that flag, States need to stay in close contact with those flag States sheltering the shadow fleet, like Gabon, Mongolia and Barbados. This contact is necessary to get their consent to the third State’s exercise of jurisdiction, to persuade them to deregister suspect dark ships or to establish whether they have the conscious intent of sheltering ships in blatant disregard of the current rules-based maritime order. Ideally, this contact should include reports under Article 94(6) UNCLOS,Footnote 108 detailing the facts in respect of which it is believed that the flag State has not properly exercised effective jurisdiction or control over its ships.
While States sheltering the shadow fleet have often validly delegated ship registration functions to private entities, it might be the case that, until diplomatic channels are actioned, they may not be fully aware of the role played by their registries in sheltering the dark fleet.Footnote 109 Naturally, where there is such a valid authorisation, the flag State is responsible for the activities of the entity operating its registry.Footnote 110 Yet, to conclusively demonstrate unwillingness, it is recommended that contact be established not only at the level of maritime administrations, but also through diplomatic and high-level channels. This is important even where State organs operate the ship registry, given the frequent disconnect between governmental organs in a State.
It is also recommended that this approach be cooperative and non-confrontational. It is in fact not the case that the shadow fleet business is beneficial for small developing States, either reputationally or financially. For instance, although the Maritime Cook Islands was one of the world’s fastest-growing registries in 2024, with around 50 ageing and Russian-trading tankers having joined in that year alone,Footnote 111 the Pacific country had projected yearly revenues from its registry of only NZD 66,000.Footnote 112 This amount would scarcely cover the legal fees of any lawsuit that might eventually be brought against it, including under Part XV UNCLOS. Therefore, it should not be assumed that the cooperation of the flag State will not be forthcoming. Flag non-recognition should be regarded as one tool among many in the strategy to combat the shadow fleet.
5. Conclusion
This article has argued that the debate on the law governing ship nationality should shift away from the flag State’s ability to exercise effective control to its willingness to exercise effective control over its ships, to maintain the public order at sea. In particular, it argued that FODs may not assert exclusive jurisdiction over their ships vis-à-vis third States, because they are unwilling to effectively control them.
In the past, the debate in relation to FOCs centred on the ability of flag States to effectively exercise their jurisdiction and control over their ships, which is crucial for maintaining the public order at sea. This article maintained that, for present purposes, the ability of a flag State to exercise effective control is not a sufficiently helpful criterion. Indeed, if a tiny island State such as the Marshall Islands has the ability to become a judicious flag State in the eyes of the international community, it demonstrates that ‘ability’ is not at issue. Instead, it has been posited that the key determinative factor is the ‘willingness’ of the flag State to exercise effective control.
Where a registry knowingly shelters ageing, unsafe and illicitly employed ships—termed by Lloyd’s List as FODs—it may be assumed that the flag State is unwilling to effectively control their ships and therewith protect the rights of third States and the public order at sea, an evolving concept which today covers a broad array of issues, especially navigational safety and environmental protection. This article has thus claimed that such unwillingness to control is contrary to the duty to protect the public order at sea and thus may permit other States to exercise jurisdiction over its vessels, in the form of non-recognition of the flag State’s exclusive jurisdiction. Importantly, non-recognition, thus conceived, does not challenge the international validity of a registration; rather, it denies that the flag State’s exclusive jurisdiction is assertable vis-à-vis other States in respect of ships that remain outside its effective control.
As demonstrated, a lawful basis for limited non-recognition of flag State jurisdiction, in situations of persistent and well-evidenced unwillingness to control the vessel, is supported by historical practice, doctrinal principle and precedent, if one interprets the Saiga (No 2) decision of ITLOS as being limited to ruling out challenges to the validity of ship registration. Such, non-recognition must be exercised cautiously: it should be embedded in procedures that prioritise fact-finding (including reports under Article 94(6) UNCLOS), diplomatic engagement and registry information-sharing.
It is true that this article dealt with the specific case of FODs in terms of assessing willingness. However, the turn from ability to willingness might benefit the international maritime community as a whole. This reflects the gradually increasing trust and cooperation with bona fide open registries, including FOCs, valuing their commitment and distinguishing them from irresponsible registries taking advantage of a sui generis regulatory environment.
Acknowledgements
The author wishes to thank the Centre for International Law at the National University of Singapore, in particular Professor Robert Beckman and the Ocean Law and Policy Team, for their guidance and support during the preparation of this article. This research has been funded by the Singapore Maritime Institute (SMI-2023-MA-03).
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