Australian Year Book of International Law
The culmination of centuries of debate and conflict in the law of the sea, the 1982 United Nations Convention of the Law of the Sea (UNCLOS), was intended to establish a comprehensive regulatory framework for all ocean uses. Its complex allocation of jurisdictional competences as between coastal and other states was intended to provide a workable regime by which its provisions could be enforced. The regime respected, on the one hand, the interests of flag states, in particular the major maritime powers, in their vessels’ free use of the seas and, on the other hand, the economic, resource and security interests of coastal states. Under the UNCLOS, except in limited circumstances where coastal state jurisdiction is provided for, and subject to specific exceptions, the flag state of a vessel enjoys exclusive jurisdiction to enforce against its vessels. In theory, therefore, a vessel is always subject to the jurisdiction of at least one state which has responsibility for it under international law and is therefore expected to ensure its compliance with international obligations. In practice, however, one of the most intractable questions in the law of the sea, as in other areas of international law, has been the question of enforcement and, in particular, what steps may be taken by non-flag states in situations where the flag state of a vessel is either unwilling or unable to comply with its international obligations.
In concluding his 1986 examination of the then recently-adopted UNCLOS regime relating to jurisdiction and enforcement against delinquent vessels, Professor Shearer noted that state practice and jurisprudence would be needed to provide content to the complex and often vague provisions of the Convention. Some 20 years on, the purpose of this essay is to examine the state practice and jurisprudence in respect of delinquent vessels in two contentious areas, fisheries and disarmament. In particular, this paper focuses on the issue of non-flag state enforcement in high seas fisheries and in respect of the interdiction at sea of vessels suspected of transporting weapons of mass destruction. At first blush, these two topics may appear unlikely bed-fellows. However, as will be seen, they both illustrate a growing trend towards assertions of a customary right of non-flag state enforcement. The consistency of these assertions with the UNCLOS and general international law will be examined and a preliminary assessment offered as to their status as new normative orders. While exceptions to the general rule of flag state enforcement on the high seas may arise as a result of the development of customary international law, acceptance of a new rule allowing for non-flag state enforcement in particular cases should be carefully weighed against the needs and desires of the international community and the underlying notion of legitimacy in international law. It will be concluded that non-flag state enforcement in the high seas fisheries context may meet the test of legality in certain circumstances, but this is not yet the case in the disarmament context.
In the context of international law, enforcement may be defined as the ‘process of compelling compliance with rules set out in an international agreement’. The object of enforcement is to compel constraint of behaviour in such a way as to promote conformity with prescribed rules in order to make adherence to the rule more attractive than violation. Defined in this way, enforcement really consists of two elements: control and sanction. Control refers to the processes of invoking compulsion in order to achieve the sought-after compliance and includes, inter alia, policing activities such as surveillance, interdiction, boarding and inspection either at sea or in port, and possibly detention pending further investigation. Sanction refers to the formal application of the law through judicial or other processes and includes actions taken to prosecute and punish non-compliance.
Non-flag state enforcement (hereafter referred to as non-flag enforcement) thus refers to the exercise of these elements by a state against vessels flying the flag of another state. This can include a coastal state, a port state where that state is different from the coastal state, or any other state, which is not the flag state of the vessel. A detailed analysis of the development of non-flag state enforcement would involve analysis of both the control and sanction elements independently of each other. However, for the purposes of this brief review the term ‘enforcement’ is used here in its generic sense as referring at once to either or both of these elements.
It is trite law that non-flag enforcement is permitted with the consent of the flag state. That consent may be given in ad hoc cases or, in a more formal sense, in advance in a treaty. In this respect it is important to note that non-flag enforcement already forms a significant part of the jurisdictional balances in the UNCLOS.
Within internal waters coastal states enjoy full territorial sovereignty over their own and other states’ vessels. In their territorial sea, coastal states enjoy full sovereignty, including enforcement jurisdiction, subject to the right of innocent passage. Beyond the territorial sea and within the contiguous zone coastal states may exercise the control necessary to prevent infringements of their customs, fiscal, immigration or sanitary laws by inbound vessels. They can also take enforcement action against outbound vessels, which have committed infringements of those laws while in their territorial sea or internal waters. Additionally, within the exclusive economic zone (EEZ) coastal states enjoy sovereign rights over, and enforcement jurisdiction in respect of, the exploration and exploitation of the living and non-living natural resources of the EEZ. Likewise, coastal states enjoy a measure of enforcement jurisdiction in respect of certain activities on the extended continental shelf.
On the high seas the UNCLOS specifically provides for non-flag enforcement in cases of piracy, slave trading, unauthorised broadcasting, and stateless vessels. Other treaty and customary regimes allow for non-flag enforcement in cases of illicit drug trafficking, self-defence, intervention in the case of accidents at sea, and in support of sanctions or blockades adopted pursuant to chapter VII of the UN Charter. The right of non-flag enforcement is also conferred by the UNCLOS on non-flag port states, which are empowered to investigate and take proceedings against vessels voluntarily within their port in respect of any discharge by such vessel on the high seas in violation of applicable international rules and standards.
In all other cases, however, the UNCLOS prescribes flag-state jurisdiction. In particular, on the high seas, enforcement jurisdiction rests exclusively with the flag state except to the extent that it is expressly circumscribed by provisions in international agreements or as otherwise provided for in the UNCLOS. However, this exclusivity of flag-state jurisdiction has started to come under pressure in the fisheries and disarmament contexts as states attempt to find effective means of dealing with delinquent vessels flagged in states either unwilling or unable to ensure compliance by their vessels with their international obligations.
The availability of non-flag enforcement in the fisheries context arises both directly and indirectly from the provisions of the UNCLOS. In the former case, fishing activities are specifically exempted from the innocent passage regime of the territorial sea and a coastal state may therefore arrest any vessel for violation of its fisheries laws within its territorial sea. In addition, the coastal state may take such measures as may be necessary to ensure compliance with its laws and regulations relating to the natural resources of the EEZ, including boarding, inspection, arrest of vessels, judicial proceedings, and the right of hot pursuit, subject only to the obligation of prompt release of the vessel upon payment of reasonable security and the requirement that violation of fisheries laws not be punished by imprisonment or corporal punishment. In other words, the coastal state may take enforcement action against vessels from other states fishing illegally in its EEZ.
Non-flag enforcement also arises from the UNCLOS, albeit more indirectly, in the high seas fishing context. All states have the right for their nationals to fish on the high seas subject only to: their treaty obligations; the rights, duties and interests of coastal states as provided for in articles 63(2) and 64 to 67 of the UNCLOS; and the duties of conservation, cooperation and non-discrimination set out in articles 117 to 120. Within these qualifications lie the roots of non-flag enforcement as an exception to flag state enforcement in the high seas fisheries context.
The obligations of conservation and cooperation in high seas fisheries have predominantly manifested themselves in the establishment of a range of regional fisheries management organisations (RFMOs), which seek to regulate exploitation of either particular ocean spaces or particular species through the adoption of various regulatory measures. Many of the constitutive treaties of these organisations provide the jurisdictional basis for aspects of non-flag enforcement, including, in particular, non-flag at-sea boarding and inspection. In some cases the detail of the non-flag regime is expressly set out in the treaty. Thus, the 1994 Convention on the Conservation and Management of Pollock Resources in the Central Bering Sea specifically establishes a regime for non-flag at-sea boarding and inspection. The 1992 Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean goes even further and provides for seizure and detention or arrest of non-flag vessels and persons on board.
Alternately, the treaty may call for the establishment of a non-flag enforcement regime, which is to meet certain stipulated criteria. The 1978 Convention on Future Multilateral Cooperation in the Northwest Atlantic Fisheries, the 1980 Convention on the Conservation of Antarctic Marine Living Resources, and the 1966 International Convention for the Conservation of Atlantic Tunas, all contain provisions stipulating the elaboration and adoption of non-flag boarding and inspection schemes, as do the 2000 Convention on the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean, the 2001 Convention on the Conservation and Management of Fishery Resources in the South East Atlantic, and the 2000 Framework Agreement for the Conservation of Living Marine Resources of the High Seas of the South Pacific.
More controversially, non-flag enforcement schemes have been adopted in the absence of express treaty provisions pursuant to the general managerial or conservatory powers granted to RFMOs by their constitutive treaties. The North East Atlantic Fisheries Commission’s (NEAFC) Control and Enforcement Scheme, which provides for non-flag at-sea boarding and inspection, finds its legislative basis in the provisions of NEAFC’s constitutive treaty, the 1980 Convention on Future Multilateral Cooperation in the North-East Atlantic Fisheries. This treaty empowers the Commission to adopt recommendations ‘concerning measures of control ... for the purpose of ensuring the application of this Convention and any recommendations adopted thereunder’.
Non-flag port state controls have similarly been adopted by a number of RFMOs despite the lack of reference to them in the UNCLOS or the constitutive treaties of RFMOs. Admittedly, the legal basis for port state control or enforcement is different, resting as it does on the customary right of states to deny access to their ports in respect of fishing vessels. Nevertheless, a natural corollary of the right to control is the right not to control. The lucrative nature of port-servicing facilities and the dictates of reciprocity and friendly relations have provided ample excuse for a reluctance on the part of many states to adopt port controls. Thus, a number of RFMOs have adopted mandatory port state control schemes pursuant to their general managerial mandates. Compulsory reciprocal port inspection was adopted in the Northwest Atlantic Fisheries Organisation (NAFO) in 1995 and in the Commission for the Conservation of Antarctic Marine Living Resources (CCAMLR) in 1998. The International Commission for the Conservation of Atlantic Tuna (ICCAT) has had a scheme in existence since 1978, while the Indian Ocean Tuna Commission (IOTC) adopted a port control scheme in 2002.
At the global level articles 20 to 23 of the 1995 UN Fish Stocks Agreement (FSA) provide the basis for non-flag enforcement both at sea and in port. Importantly, the overall effect of the FSA is that all states are to cooperate to ensure compliance with and enforcement of the conservation and management measures adopted by RFMOs, regardless of whether they are themselves a member of the relevant RFMO. Where flag states fail to so cooperate, non-flag states may take certain enforcement action against their vessels.
A comprehensive analysis of practice under these various schemes has already been conducted elsewhere. That analysis reveals that non-flag enforcement is becoming mainstream in a wide range of RFMOs and while the requirement of flag state consent to such action is not wholly negated that consent will now be aggressively pursued either bilaterally, multilaterally or on an ad hoc basis, and that there is now a general expectation that such consent will be granted. Nevertheless, treaty regimes only operate inter partes. The more interesting question is whether any legal basis exists for a general right of non-flag enforcement beyond these consent based examples.
The 1992 UN Driftnet Moratorium represents one possible basis for the assertion of non-flag enforcement jurisdiction. However, the resolutions establishing the moratorium only deal with large-scale pelagic driftnet fishing. In addition, they do not, per se, deal with enforcement. Rather, they note the importance of compliance and merely encourage states ‘to take measures, individually and collectively, to prevent large-scale pelagic driftnet fishing on the high seas’. The Driftnet Moratorium has certainly spawned practice relevant to the issue of non-flag enforcement. For example, the United States-China Shiprider Memorandum of Understanding, which provides authority for non-flag enforcement and establishes reciprocal boarding procedures for United States or China flagged vessels suspected of illegal high seas driftnet fishing, expressly refers to the Driftnet Moratorium. Nevertheless, the legal authority for the enforcement action is found not in the Driftnet Moratorium resolutions, but in the subsequent bilateral agreement. Similarly, the legal authority for the aggressive non-flag enforcement activities of the members of the North Pacific Anadromous Fish Commission (NPAFC) rests on the unique combination of article 66 of the UNCLOS and the provisions of the Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean. In other words, the Driftnet Moratorium and the UN General Assembly resolutions adopting it do not provide, by themselves, a sufficient jurisdictional basis for the exercise of non-flag state enforcement.
More telling is the practice emerging in RFMOs with respect to non-flag actions being taken against third parties, regardless of whether the states concerned are party to the FSA. Here, too, state practice indicates an increasing assertion of a right to aggressively pursue consent for non-flag enforcement by members of RFMOs against vessels flagged in non-member states. The basis for such aggressive pursuit of consent is clearly laid in a number of RFMOs. The NPAFC and North Atlantic Salmon Conservation (NASCO) find support in the UNCLOS article 66 prohibition on high seas salmon fishing. The NPAFC finds further support in the Driftnet Moratorium. Beyond these, ICCAT,  the IOTC, NEAFC,  NAFO and CCAMLR have all adopted measures that deem any non-contracting party vessel sighted fishing or trans-shipping in the relevant regulatory area to be undermining the effectiveness of that organisation’s conservation and management measures. Attempts are to be made to inform sighted vessels and their flag state that they have been seen. Although not stated, the implication must be that non-flag state inspection vessels may then request the master’s or the flag state’s consent to board and inspect, either expressly or through the revocation or denial of flag thereby rendering the vessel stateless. This implication is supported by actual practice in a number of RFMOs. While it is as yet unclear whether an obligation to consent exists, there is clear evidence of an expectation that consent will be given or, if it is not, that the flag state will itself take effective measures to stop the vessel from engaging in the offending conduct. In other words, at least in the context of RFMOs, non-flag enforcement is an emerging phenomenon in the high seas fisheries context; no longer prohibited, it appears, on the contrary, to be both accepted and expected, if not yet wholly obligatory in all circumstances.
The assertion of non-flag enforcement in the disarmament context is of more recent vintage, and has arisen despite the absence of any direct or indirect provision for its assertion in the UNCLOS. Indeed, to the contrary, the issue of disarmament was expressly and deliberately excluded from the UNCLOS negotiations at the insistence of the United States and other major military powers who sought to ensure preservation of the greatest possible freedom of navigation for their naval and other vessels. Disarmament and demilitarisation of the oceans were left to be dealt with in other fora. A number of multilateral treaties have been entered into dealing with various aspects of the demilitarisation, and particularly denuclearisation, of the seas and the sea-bed, which either prohibit certain activities entirely for their states parties or prohibit certain activities in certain areas. Recently, however, attention has been focused on the issue of proliferation of weapons of mass destruction (WMD) such as nuclear, chemical and biological weapons and the need to ensure such weapons, their delivery systems and related materials do not fall into the hands of terrorists or ‘rogue’ states. A right of non-flag enforcement – or at-sea interdiction – has been invoked in aid of this objective. This section explores the potential legal bases for the assertion of such a right.
It will be recalled that within the territorial sea, vessels are entitled to the right of innocent passage, which is passage that is not prejudicial to the peace, good order or security of the coastal state. It is the nature of the activity in which a vessel is engaged, and not the nature or identity of the vessel concerned that determines innocence. To that end an exhaustive list of activities, which prima facie constitute non-innocent passage is included. Germane to this enquiry, innocence will be lost where vessels engage in the threat or use of force against the coastal state, violations of customs, immigration, sanitary and fiscal laws of the coastal state, and any other activity not having a direct bearing on passage. In such cases, the coastal state may take the necessary steps to prevent passage and may arrest the vessel for any violation of the coastal state’s laws. In other words, in cases of non-innocent passage a right of non-flag state enforcement arises directly under the UNCLOS regime.
The otherwise plenary jurisdiction of the coastal state in relation to the territorial sea is, however, somewhat circumscribed in that while it may enact legislation in respect of a wide range of activities, in a number of circumstances that legislation must be consistent with generally accepted international rules and standards. In addition, the mere carriage of nuclear or other inherently noxious substances does not render passage non-innocent. Such vessels are obliged only to comply with documentary and precautionary requirements established by international agreements. Importantly, nothing in the UNCLOS prohibits the shipment of WMD or related materials. Thus, unless a vessel carrying such materials is engaged in activities that otherwise render its passage non-innocent, the coastal state has no right of non-flag enforcement. Importantly, too, the otherwise plenary criminal jurisdiction that the coastal state may exercise over foreign ships in its territorial sea is circumscribed by the requirements that such jurisdiction not be exercised in respect of crimes occurring in the territorial sea unless the consequences of the crime extend to the coastal state, or disturb the peace of the state or the good order of the territorial sea, or if the master of the ship or the flag state has requested it, or if the measures are necessary to suppress drug trafficking. The requirement that the crime have a direct consequence for the coastal state has the potential to severely limit the right of non-flag enforcement by the coastal state, particularly where the coastal state is used merely as a transit point for materials carried by vessels not otherwise engaged in non-innocent passage.
Beyond the territorial sea, with the exception of the right of coastal state enforcement in the contiguous zone in respect of violations of the state’s customs, immigration, fiscal and sanitary laws, vessels generally enjoy the freedom of navigation and are subject only to the exclusive jurisdiction of their flag state. This freedom of navigation, the oldest recognised high seas freedom, is limited only by the requirement that it be exercised with due regard for the interests of other states and that the high seas are to be reserved for peaceful purposes. No definition of ‘peaceful purposes’ is given in the UNCLOS but article 301 does provide that states parties shall refrain from the use of force in any manner inconsistent with international law or the UN Charter. This provision is generally understood as forbidding only aggressive actions at sea. In other words, the legal basis for non-flag enforcement or interdiction beyond the territorial sea in support of disarmament activities does not arise from, but may be expressly forbidden by, the UNCLOS. Its legal basis must be found in other principles of international law.
One locus for the legal basis of interdiction activities lies in UN Security Council resolutions mandating naval interdiction operations in support of UN sanctions resolutions. In these cases chapter VII of the UN Charter provides the basis upon which the Security Council may adopt a range of measures to restore and maintain international peace and security including, inter alia, blockades at sea and embargoes or other measures specifically aimed at interruption of ocean-going commerce for the purpose of enforcing sanctions. Such measures, when adopted under chapter VII are both mandatory and, pursuant to article 25 of the Charter, binding on all member states. It has been argued that not only are UN-mandated naval interdiction operations legitimate both within and beyond the territorial sea, but that these operations do not, themselves, constitute a violation of the right of innocent passage for the purposes of allowing the coastal state to take action or the requirement of peaceful purposes. A Security Council naval interdiction operation, authorised under chapter VII of the UN Charter as a peace-support operation, cannot, by definition, be characterised as having a prejudicial character.
In the absence of a Security Council mandate the legal basis for non-flag interference with shipping is less clear. Certainly, such interference can be based on a treaty right. In this respect the Maritime Safety Committee of the International Maritime Organisation is currently discussing amendments to the 1988 Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation and its Protocol to include strengthened measures to prevent acts of terrorism that threaten the security of passengers and crews and the safety of ships. The proposed provisions allowing for non-flag boarding have, however, been contested on the basis of their conflict with the fundamental principles of freedom of navigation and exclusive flag state jurisdiction. In any event, the amended convention will only operate inter partes.
More controversial is the Proliferation Security Initiative (PSI) announced by the United States on 31 May 2003. The PSI effectively aims to regularise interdiction efforts such as the December 2002 high seas interdiction by the Spanish navy, acting at the behest of the United States, of the apparently un-flagged vessel the So San, which was found to be carrying scud missiles and conventional warheads concealed under bags of cement. The vessel was released when Yemen announced that it had purchased the missiles. Since no rule of international law renders the production, sale or transport of missiles unlawful the shipment could not lawfully be interfered with.
The PSI seeks to constrain proliferation of WMD through a number of steps including import, export and port controls. Relevant to this discussion is the Statement of Interdiction Principles adopted by the states participating in the PSI, which clearly envisages permitting interdiction of shipments in the territorial sea or on the high seas aimed at stopping the flow of ‘WMD, their delivery systems, or related materials … to and from states and non-state actors of proliferation concern.’ The Principles call on participating states to take specific actions in support of interdiction efforts, including:
• either on their own initiative or at the request of another state to board and search their own flag vessels in their internal waters, territorial seas or areas beyond the territorial seas of any other state and seize relevant cargoes;
• seriously to consider giving consent to non-flag state boarding and inspection of their vessels and seizure of relevant cargoes; and
• to stop and/or search suspect vessels in their internal waters, territorial seas or contiguous zones and enforce conditions on suspect vessels entering or leaving their ports, internal waters or territorial seas.
Interdiction carried out by flag states on own flagged vessels either within their own waters or on the high seas will not fall foul of the UNCLOS. Likewise, interdiction of stateless vessels will not violate the UNCLOS. However, the PSI raises the theoretical possibility of interdiction of non-flag vessels within the territorial sea of the interdicting state or on the high seas, both of which do pose a significant challenge to the UNCLOS regimes of innocent passage and freedom of navigation, particularly given that mere transportation of WMD, missile delivery systems, and related materials can be considered neither non-innocent passage nor a non-peaceful purpose under the UNCLOS.
Clearly, where domestic legislative authority exists, a flag state may request the assistance of another state in interdicting its own vessels either on the high seas or within the territorial or internal waters of that other state. This consent may be given on an ad hoc basis or in a treaty such as the Shipboarding Agreements between the United States and Panama, the United States and Liberia, (respectively the largest and second-largest flag registries in the world) and the United States and the Republic of the Marshall Islands, all of which provide authority for non-flag enforcement procedures in respect of vessels suspected of carrying illicit shipments of WMD, their delivery systems or related materials.
The more difficult issues, however, are whether, in the absence of a domestic or international legal rule prohibiting the possession or shipment of these items, a flag state, which is not party to such an agreement, is obliged to interdict its own flag vessels and whether, should they not be willing or able to do so, they are obliged to give consent to other states that are willing and able to do so, and what the effect of any refusal to give consent will be. For PSI participants, the Interdiction Principles arguably represent a relocation of the requirement of consent to non-flag enforcement action in the WMD context. In other words, while the requirement of flag state consent may not be wholly negated, even absent a treaty obligation, that consent will now be aggressively pursued, and there is an expectation that such consent will be granted. It is, however, unclear what the effect of refusal to consent will be.
Even more problematic is whether this result applies to states that are not participants in the PSI. This is particularly important given the admitted focus on interdicting vessels of North Korean origin. Indeed, North Korea has declared that it will regard any such interception as an act of war. While a number of interdiction exercises have been carried out by the participants in the PSI with further exercises planned, the PSI participants have announced an intention not to release information about actual interdictions. From what little information is available it appears that actions taken to date against North Korean vessels and shipments to or from that country have been dealt with in port pursuant to port states’ rights rather than by way of interdiction at sea.It is therefore impossible to assess whether any state practice is emerging to support a general right of non-consensual, high seas non-flag interdiction as against non-PSI participants.
The previous sections have detailed the developing assertions of a customary right of non-flag enforcement in the high seas fisheries and disarmament contexts. However, before accepting such a radical departure from the centuries-old rule of flag-state jurisdiction, it is appropriate to test the assertion of right in both cases not only against international law but also against the underlying concept of legitimacy.
The legal basis for a customary right of non-flag state enforcement in the high seas fisheries context rests on the twin pillars of flag-state responsibility and the obligation to cooperate with RFMOs. It will be recalled that the UNCLOS deals only in the most general terms with the high seas fishing regime, the legal parameters of which have been developed within the overall UNCLOS framework through subsequent multilateral treaties including the FAO Compliance Agreement and the FSA, numerous declarations including Agenda 21, the Declaration of Cancun and the International Plan of Action to Prevent, Deter and Eliminate Illegal, Unreported and Unregulated Fishing, as well as through state practice by both members and non-members of RFMOs. This practice increasingly reveals acceptance of a customary rule that flag states may only authorise their vessels to fish when they can effectively exercise their flag state responsibilities over them to ensure compliance with measures adopted by RFMOs.
Based on these developments it has been argued that it may now be taken as an aspect of flag state responsibility that flag states have, in fact, implicitly consented to non-flag enforcement by members of RFMOs where their vessels are fishing in contravention of the measures adopted by that RFMO and where the flag state is unwilling or unable to act, regardless of the existence or otherwise of an established scheme for non-flag state enforcement within the RFMO or the application of the FSA. Moreover, the practice reveals acceptance of a customary duty to cooperate with RFMOs, an essential component of which is now the requirement for non-member flag states to respect the measures adopted by RFMOs either through compliance or by restraint from fishing. Where non-member flag states either fail to ensure compliance or restraint from fishing, practice indicates they may be, as a matter of customary international law, taken to have consented to non-flag state enforcement action by member states of a RFMO acting under its auspices.
In terms of its underlying legitimacy, it appears that a rule permitting non-flag enforcement on the high seas by members of RFMOs of the conservation and management measures adopted by those RFMOs against both members and non-member states where the flag state is unwilling or unable to enforce those measures has a high degree of legitimacy. Hence, its acceptance as a positive rule of international law should be promoted. The rule can be clearly articulated and circumscribed. It would apply to all states and all vessels fishing on the high seas and to the extent inability or unwillingness produces a degree of indeterminacy, procedures can be, and indeed are being, adopted within RFMOs to resolve or define the parameters of the rule’s application. The rule has already been accepted and implemented in the practice of states and it rests firmly on the universally recognised and consistently articulated needs of the international community to ensure the long-term conservation and sustainable use of high seas fisheries resources.
Furthermore, the rule is a necessary progression of an international legal order that first mandates long-term and sustainable conservation and management of high seas resources, then institutionalises RFMOs to carry this out, then provides RFMOs with the authority to adopt the necessary conservation and management measures, and then allows RFMOs to exercise the authority necessary to ensure compliance. The rule is also a rule of last resort, to be used only in exceptional circumstances and in a wholly non-discriminatory fashion, in that it is designed to enforce compliance by vessels of all states regardless of membership in the RFMO. Finally, the rule is an extension of the normative provisions of the UNCLOS that respects flag state jurisdiction subject to certain exceptions. In this respect the rule is an integral, albeit exceptional, development.
This argument of legitimacy presupposes the fulfilment of a number of criteria. Quite apart from objections to non-flag enforcement grounded in practical realities relating to distance, cost, nature of the fishery, existence or otherwise of appropriate measures, and appropriateness of alternate mechanisms, the legitimacy of the assertion of right will rest on the underlying legitimacy of the measures sought to be enforced. In this respect issues such as the degree of agreement on specific conservation and management measures, the availability and use of objection procedures, the adequacy of decision-making procedures, and rights to participation and allocation will be relevant. In addition, consistency and non-discrimination in application is necessary such that members as well as non-members are equally subject to both the management and enforcement regime. All of these criteria have been or are currently being addressed in an ongoing manner in RFMOs. Given the accepted institutionalisation of RFMOs as the recognised regulators of high seas fisheries, assuming these issues are either effectively dealt with within the RFMO or adequate procedures are in place for doing so, there seems no basis on which to oppose consolidation of the rule.
The legal basis for a customary right of non-flag enforcement in the disarmament context, on the other hand, if one exists, rests wholly outside the UNCLOS regime. One argument is that it rests on the right of self-defence. This argument has, however, been heavily challenged as both an unwarranted and an unwise expansion of the doctrine of self defence which, as articulated in article 51 of the UN Charter, only applies in the event an actual armed attack occurs. Even if the existence of a customary right of anticipatory self defence is accepted, it is argued that interdiction of shipments cannot possibly meet the accepted criteria of ‘instant, over-whelming and leaving no choice of means and no moment for deliberation’. Attempted justifications on the basis of the UN Security Council Presidential Statement of January 1992 are likewise dismissed on the basis that such statements, interesting though they may be, have no legal significance.
More persuasive are arguments based on the international community’s growing acceptance of the undesirability of WMD as evidenced in the negotiation of and participation in treaty regimes such as the Non-Proliferation Treaty, the Biological Weapons Convention and the Chemical Weapons Convention. However, to the extent that the PSI is targeted on North Korea it must be remembered that North Korea is not a party to the Non-Proliferation Treaty. Further, while proliferation, transport and sale of biological and chemical weapons may be prohibited for states parties to these conventions, the conventions do not provide a legal basis for high seas interdictions even inter partes. Moreover, as recognised in the Legality of the Threat or Use of Nuclear Weapons Case, the conventions alone cannot provide sufficient evidence of state practice or opinio juris from which a customary norm of prohibition and accompanying right of interception might have arisen, particularly in the face of inconsistent practice by the very states alleging the rule.
Likewise, the recently passed UN Security Council resolution 1540 provides little support. That resolution, adopted under chapter VII of the Charter, identifies the threat of illicit trafficking in WMD and related materials as a threat to international peace and security and requires states, inter alia: to refrain from providing support to non-state actors seeking to acquire, manufacture, possess, transport, transfer or use these materials; to adopt and enforce laws prohibiting non-state actors from acquiring or otherwise coming into contact with these materials; and to establish and enforce effective domestic controls to prevent proliferation including appropriate accounting and recording procedures, physical protection measures, effective border control and law enforcement efforts and export and trans-shipment controls. However, unlike the specific UN Security Council ‘blockade’ resolutions referred to above, nowhere in resolution 1540 are states given the express authority to conduct non-flag interdiction operations. Rather, cooperative action to prevent trafficking in WMD and related materials is to be taken in accordance with national legislation and consistent with international law. Since international law does not recognise a general right of non-flag interdiction, and the shipment of components of WMD, their delivery systems or related materials is not per se illegal under international law, such action under the PSI cannot, prima facie, be lawful. It therefore remains to be seen whether state practice pursuant to the PSI and resolution 1540 will alter the customary position such that a right of non-flag interdiction of shipments of WMD, their delivery systems or related materials will arise.
In the meantime, however, the issue of legitimacy is a vexed one for the PSI and its participants. To begin with, there is no fixed definition of WMD in international law and the descriptor of ‘delivery systems or other related materials’ is so broad as to include a vast range of dual-use items, the shipment of which will be intended for perfectly ‘innocent’ purposes. Indeed, it has been estimated that up to 95 per cent of the ingredients used for WMD, their delivery systems and related materials are legitimate dual-use materials. While it may be possible to ‘know an illicit shipment when you see it’, in the absence of any transparent, internationally accepted procedures for ‘knowing it’, which ensure non-interference with innocent shipments, the purported rule’s reach is too broad.
Moreover, as manifested in the PSI the rule is both capricious and discriminatory on a number of levels. For example, it is aimed only at non-state actors and states of ‘proliferation concern’. No procedural framework is provided for identifying those actors or states of concern or for assessing the validity of the intelligence upon which assertions of concern are based. In addition, PSI participant states themselves are among the states responsible for the design, manufacture, sale, transport and use of the materials sought. There is a very real appearance that PSI states seek merely to appropriate unto themselves recognised rights that they would deny to others. In this respect, the actions of the United States in failing to ratify the Comprehensive Nuclear Test Ban Treaty and in continuing to pursue development of new low-yield nuclear weapons strike at the very heart of the PSI’s legitimacy.
Finally, non-flag, non-consensual interdiction of commercial shipping is wholly inconsistent with both the UNCLOS and the current legal regime relating to disarmament. Particularly given that such interdictions may, themselves, constitute a violation of both the peaceful purposes requirement in the UNCLOS and the prohibition on the use of force in the UN Charter, great care should be taken in promoting a rule permitting non-consensual non-flag enforcement or interdiction by states participating in the PSI against vessels of non-participating states suspected of being engaged in the transportation of WMD, their delivery systems or related materials.
It is acknowledged that this argument of non-legitimacy may be overcome by evidence of state practice in conformity with the purported rule. In this respect, a number of commentators have suggested a range of steps that, if followed, would help to overcome the ‘legitimacy deficit’ currently faced by the PSI. These include: increasing transparency; establishing effective mechanisms for determining when, where, how and against whom interceptions should occur; ensuring non-discrimination and equal application to all states; seeking more explicit UN Security Council authorisation; continuing support of other and more effective non-proliferation measures; and pursuing the root causes of proliferation, including activities undertaken by PSI participants themselves. To date, however, there is no indication that these recommendations having been accepted by PSI participants and, in the absence of information relating to interdictions, it is impossible to tell whether they will be. It does appear, however, as evidenced by the agreements between the United States and Panama, Liberia and the Marshall Islands, that PSI participants are mindful of the need for express consent to non-flag interdictions in cases where the vessel is not stateless. It is too early to tell whether the locus of this consent will shift from positive requirement to negative implication as a matter of custom. Ultimately, given the legal, and very real practical, difficulties in interdictions, particularly on the high seas, the greatest use of the PSI may rather be made in the context of cooperative and harmonised port-state enforcement and information sharing.
This essay has examined the burgeoning state practice in relation to non-flag enforcement against delinquent vessels in the high seas fisheries and disarmament contexts. It has been argued that while non-flag enforcement in the former case may have reached a level of acceptance in international law such that it might now be considered a rule of customary international law, this threshold has not yet been reached in the latter case, particularly in the context of the PSI. Indeed, as presently constituted, non-consensual non-flag high seas interdictions pursuant to the PSI would constitute direct violations of international law. That this apparently contradictory position should be reached is both a function of current state practice and the particular legal regimes involved.
Admittedly, non-flag enforcement is neither the only nor, in many cases, the preferred method of enforcing against delinquent vessels on the high seas. However, in situations where a flag state is either unwilling or unable to ensure that its vessels comply with their international obligations then it may be the enforcement method of last resort. In the fisheries context certain delinquent behaviour must be stopped where it occurs, that is, on the high seas. In the disarmament context illicit shipments may be better intercepted in port. In any event, in both cases, to echo the words of Professor Shearer, state practice and jurisprudence is still needed to establish the parameters of a right of non-flag enforcement against delinquent vessels on the high seas.
[∗] Associate Professor, Faculty of Law, University of New South Wales.
 United Nations Convention on the Law of the Sea (10 December 1982), 1833 UNTS 3 (UNCLOS).
 UNCLOS arts 86, 87 and 92.
 I Shearer, ‘Problems of Jurisdiction and Law Enforcement Against Delinquent Vessels’ (1986) 35 International Law and Comparative Quarterly 320.
 C Joyner, ‘Compliance and Enforcement in New International Fisheries Law’ (1998) 12 Temple International and Comparative Law Journal 271, 275.
 P Sands, ‘Compliance with International Environmental Obligations: Existing International Legal Arrangements’ in P Roderick, J Cameron and J Werksman (eds), Improving Compliance with International Environmental Law (1996) 48, 58-68; O Young, Compliance and Public Authority: A Theory of International Applications (1979) 20.
 See J E Carroz and A G Roche, ‘The International Policing of High Seas Fisheries’ (1968) Canadian Yearbook of International Law 61.
 For a detailed analysis of non-flag state enforcement in the high seas fisheries context that distinguishes between these elements see, R Rayfuse, Non-Flag State Enforcement in High Seas Fisheries (2004).
 UNCLOS arts 2 and 8. It should be noted that this is subject to the important limitation expressed in art 8(2) whereby within waters enclosed as internal waters by straight baselines drawn in accordance with art 7, which had previously not been considered as such, the right of innocent passage persists.
 UNCLOS arts 2 and 17-19.
 Ibid art 33.
 Ibid art 56.
 Ibid arts 76 and 77.
 Ibid art 110.
 For a full discussion see Rayfuse, above n 7, 52-61.
 UNCLOS art 218.
 Ibid art 92(1).
 Ibid arts 19, 25 and 27.
 Ibid arts 56 and 73.
 Ibid art 116.
 Convention on the Conservation and Management of Pollock Resources in the Central Bering Sea (16 June 1994), 34 ILM 67, art XI.
 Convention for the Conservation of Anadromous Stocks in the North Pacific Ocean (11 February 1992) 22 Law of the Sea Bulletin 21-29, arts IV and V.
 Convention on Future Multilateral Cooperation in the Northwest Atlantic Fisheries (24 October 1978), 1135 UNTS 369, art XI(5).
 Convention on the Conservation of Antarctic Marine Living Resources (20 May 1980),  ATS 9, art X.
 International Convention for the Conservation of Atlantic Tunas (14 May 1966), 673 UNTS 63, art IX(3).
 Convention on the Conservation and Management of Highly Migratory Fish Stocks in the Western and Central Pacific Ocean (5 September 2001) 40(2) ILM 277,  ATS 15, arts 25 and 32.
 Convention on the Conservation and Management of Fishery Resources in the South East Atlantic (20 April 2001) 41(2) ILM 257, art 16(3).
 Framework Agreement for the Conservation of Living Marine Resources of the High Seas of the South Pacific <http://www.spc.org.nc/coastfish/Asides/
Conventions/SPPC.htm>, arts 8 and 13.
 Adopted by NEAFC in 1998. Report of the Seventeenth Annual Meeting of NEAFC (1998)  and annex F.
 Convention on Future Multilateral Cooperation in the North-East Atlantic Fisheries (18 November 1980), Cmnd 8474, art 8.
 T Lobach, Port State Control of Foreign Fishing Vessels, FAO Legal Papers Online No 2 (2002), <http://www.foa.org/Legal/prs-01/p029.pdf> 9.
 NAFO Port Inspection Scheme, Report of the Special Meeting of the Standing Committee on International Control (STACTIC) (May 1995) 47, Report of the Special Meeting of the Fisheries Commission and its Subsidiary Body (STACTIC) (May 1995) 79, and Report of the 17th Annual Meeting of the Fisheries Commission and its Subsidiary Body (STACTIC) (1995) 183.
 CCAMLR Scheme to Promote Compliance by Non-Contracting Party Vessels, adopted in 1997, CM 118/XVI, Report of the Sixteenth Meeting of the Commission (1997) 39  and CM 119/XVII, Licensing and Inspection Obligations of Contracting Parties with Regard to their Flag Vessels Operating in the Convention Area, adopted in 1998, Report of the Seventeenth Meeting of the Commission (1998) 45-6  and .
 ICCAT Scheme of Port Inspection, adopted 1978, ICCAT Rep 1978-79 part I (1978) 73-79 and ICCAT Rec 97-10 for a revised ICCAT Port Inspection Scheme, into force 13 June 1998. See also Rec 98-11 Concerning the Ban on Landings and Trans-shipments of Vessels form Non-Contracting Parties Identified as Having Committed a Serious Infringement, into force 21 June 1999.
 The IOTC was established in 1996 pursuant to the 1993 Agreement for the Establishment of the Indian Ocean Tuna Commission  20 ATS 20. Interestingly this only applies to non-contracting party vessels. IOTC Res 01/03 establishing a Scheme to Promote Compliance by Non-Contracting Party Vessels with Resolutions Established by the IOTC, adopted December 2001.
 1995 Agreement for the Implementation of the Provisions of the UN Convention on the Law of the Sea (10 December 1982), Relating to the Conservation and Management of Straddling Fish Stocks and Highly Migratory Fish Stocks, (4 December 1995) 24 ILM 1542,  ATS 8.
 See Rayfuse, above n 7. The conclusions in this section are taken from that study.
 Ibid 355.
 UN Driftnet Moratorium (20 December 1991) UN Doc A/Res/46/215, adopted by the General Assembly without a vote.
 Ibid .
 United States-China Memorandum of Understanding on Effective Cooperation and Implementation of UN GA Res 46/215 (1991), signed at Washington (3 December 1993) and entered into force on the same day. The MOU has been extended by exchanges of letters for periods of up to three years, the last extension being agreed to in letters dated 30 August and 31 December respectively. See Ninth Annual Report of the North Pacific Anadromous Fish Commission, 2001, 38.
 See Rayfuse above n 7, 134-136.
 I Shearer, ‘High Seas Drift Gillnets, Highly Migratory Species, and Marine Mammals’ (1992) 24 LOSI Proceedings 237.
 Rayfuse, above n 7, 344-348.
 The North Atlantic Salmon Conservation Organisation was established pursuant to the 1982 Convention for the Conservation of Salmon in the North Atlantic, TIAS 10789.
 ICCAT Rec 98-11 concerning the Ban on Landings and Trans-shipments of Vessels form Non-Contracting Parties Identified as Having Committed a Serious Infringement.
 IOTC Res 01/03 Establishing a Scheme to Promote Compliance by Non-Contracting Party Vessels with Resolutions Established by the IOTC .
 NEAFC Scheme to Promote Compliance by Non-Contracting Party Vessels with Recommendations Established by NEAFC .
 NAFO Scheme to Promote Compliance by Non-Contracting Party Vessels, art 5.
 CCAMLR Scheme to Promote Compliance by Non-Contracting Party Vessels with CCAMLR Conservation Measures.
 Rayfuse, above n 7, 347.
 Ibid 348.
 See D P O’Connell, International Law of the Sea (vol II, 1982) 825; RWG de Muralt, ‘The Military Aspects of the UN Law of the Sea Convention’ (1985) 32 Netherlands International Law Review 79; M R Shyam, ‘The UN Convention on the Law of the Sea and Military Interests in the Indian Ocean’ (1985) 15 Ocean Development and International Law 149; and P Merciai, ‘La Démilitarisation des Fond Marins’ (1984) 88 Revue Générale de Droit International Public 48.
 Eg Antarctic Treaty (1 December1959), 402 UNTS 71,  ATS 12; Treaty Banning Nuclear Weapon Tests in the Atmosphere, in Outer Space and Under Water (Partial Test Ban Treaty) (10 October 1963), 480 UNTS 43,  ATS 26; Treaty for the Prohibition of Nuclear Weapons in Latin America (Treaty of Tlatelolco) (14 February 1967), 634 UNTS 326; Treaty on the Non-Proliferation of Nuclear Weapons (1 July 1968), 10485 UNTS 729,  ATS 3; South Pacific Nuclear Free Zone Treaty (Treaty of Rarotonga) (6 August 1985) 24 ILM 1442,  ATS 32; Treaty on the Prohibition of the Emplacement of Nuclear Weapons and Other Weapons of Mass Destruction on the Seabed and the Ocean Floor and in the Subsoil Thereof (The Seabed Treaty) (11 February 1971), 955 UNTS 115,  ATS 4; African Nuclear-Weapons-Free Zone Treaty (Treaty of Pelindaba) (June 1995), (1996) 35 ILM 705; Treaty on the Southeast Asia Nuclear-Weapons-Free Zone (15 December 1995), (1996) 35 ILM 635.
 UNCLOS art 19(1).
 R R Churchill and A V Lowe, The Law of the Sea (3rd ed, 1998) 86.
 Art 19(2).
 UNCLOS art 25 and Churchill and Lowe, above n 55, 87 and 98.
 UNCLOS art 21.
 Ibid art 23.
 Ibid art 27.
 Ibid art 33.
 Ibid arts 90-92.
 UNCLOS arts 87(2) and 88.
 B A Boczek, ‘Peaceful Purposes Provisions of the United Nations Convention on the Law of the Sea’ (1989) 20 ODIL 359; Churchill and Lowe, above n 55, 431.
 A H A Soons, ‘A “New” Exception to the Freedom of the High Seas: The Authority of the UN Security Council’ in T D Gill and W P Heere (eds), Reflections on Principles and Practice of International Law (2000) 205.
 R McLaughlin, ‘United Nations Mandated Naval Interdiction Operations in the Territorial Sea?’ (2002) 51 International and Comparative Law Quarterly 249, 276-277.
 Convention for the Suppression of Unlawful Acts against the Safety of Maritime Navigation (10 March 1988), 27 ILM 668.
 Protocol for the Suppression of Unlawful Acts Against the Safety if Fixed Platforms Located on the Continental Shelf, (10 March 1998) 27 ILM 668.
 Press Release on the Discussions of the Legal Committee of the International Maritime Organisation, 88th Session, 19-23 April 2004 <http://www.imo.org/> .
 The PSI is described as an ‘activity’ not an organisation. It is not established by treaty but rather is a cooperative activity engaged in voluntarily by a number of states. Its core participants are Australia, France, Germany, Italy, Japan, Netherlands, Poland, Portugal, Spain, the United Kingdom and the United States. Since its inception, other countries such as Canada, Denmark, Norway, Singapore and Turkey have also expressed support for the initiative and become involved in varying capacities. More than 60 states are said to have voiced support for the initiative, although what that support entails is unclear. See <http://www.
 ‘US lets Scud ship sail to Yemen’ <http://www.cnn.com/2002/World/asiapcf/east/12/11/us.missile.ship/index.html> .
 Adopted at the Third Meeting of the Participants in the PSI held in Paris on 3 and 4 September 2003. The text of the Principles is available at <http://www.state.gov/t/np/rls/fs/23764.htm> .
 Statement of Interdiction Principles, preambular paragraph.
 Ibid para 4(b).
 Ibid para 4(c).
 Ibid [4(d)].
 B Freidman, ‘The Proliferation Security Initiative: The Legal Challenge’, The Bipartisan Security Group Policy Brief (2003) <http://www.gsinstitutue.org/bsg> S S Yang, ‘Legal Basis for State Interception of Shipments on High Seas: Legality of the Naval Interdiction under the “Proliferation Security Initiative”‘ (2003) <http://www.lcnp.org/disarmament/MEMO_NK_interdiction.PDF> .
 Amendment to the Supplementary Agreement between the Government of the United States of America and the Government of Panama to the Arrangement between the Government of the United States of America and the Government of Panama for Support and Assistance from the United States Coast Guard for the National Maritime Service of the Ministry of Government and Justice, signed 12 May 2004, provisionally applied from 12 May 2004, into force 1 December 2004 <http://www.state.gov/t/np/trty/32858pf.htm> .
 Agreement between the Government of the United States of America and the Government of the Republic of Liberia Concerning Cooperation to Suppress the proliferation of Weapons of Mass Destruction, Their Delivery Systems and Related Materials by Sea, signed 11 February 2004, provisionally applied from 11 February 2004, into force 9 December 2004 <http://www.stae.gov/t/np/trty/32403pf.htm> .
 Agreement between the Government of the United States of America and the Government of the Republic of Marshall Islands Concerning Cooperation to Suppress the Proliferation of Weapons of Mass Destruction, Their Delivery Systems and Related Materials by Sea, signed 13 August 2004, provisionally applied form 13 August 2004, into force 24 November 2004 <http://www.stae.gov/t/np/trty/35237.htm> .
 J Colman, ‘US plans “Cuba lite” blockade on North Korea’ Daily Telegraph (27 April 2003); A Crabb, ‘Howard talks tough on North Korea’ The Age (14 July 2003).
 N Kralev, ‘US Seeks Asian Aid for Ship Searches’ Washington Times (17 June 2003).
 For information on interdiction exercises see <http://www.globalsecurity.org/military/ops/psi.htm> .
 See interview with John Bolton, US Undersecretary of State for Arms Control and International Security <http://www.armscontrol.org/aca/midmonth/November/Bolton.asp> .
 See the Strategic Geography map at <http://www3.oup.co.uk/stsurv/current/pdf/VI.pdf> .
 Agreement to Promote Compliance with International Conservation and Management Measures by Fishing Vessels on the Hight Seas (24 November 1994) 33 ILM 968,  ATS 26.
 Report of the United Nations Conference on Environment and Development, Rio de Janiero (3-4 June 1992) vol I, annex II.
 Reproduced as annex 2 to the Report of the Technical Consultation on High Seas Fishing, FAO Fisheries Report No 484 (1992).
 Adopted by the UN Food and Agriculture Organisation in June 2001 <http://www.fao.org/DOCREP/003/y1224e/1224e00.htm> .
 Rayfuse, above n 7, 371.
 Ibid 372.
 Rayfuse, above n 7 359-364.
 Ibid 364-372.
 Yang, above n 77, 8-9.
 Friedman, above n 77, 6.
 Yang, above n 77, 10-12.
 Treaty on the Non-Proliferation of Nuclear Weapons, (1 July 1968), 729 UNTS 161,  ATS 17.
 Convention on the Prohibition of Development, Production and Stockpiling of Bacteriological (Biological) and Toxin Weapons and on their Destruction, (10 April 1972), 1015 UNTS 163,  ATS 23.
 Convention on the Prohibition of Development, Production and Stockpiling of Chemical Weapons and on their Destruction, (13 January 1993), 31 ILM 800,  ATS 3.
 North Korea withdrew from the NPT on 10 January 2003.
 Legality of the Threat or Use of Nuclear Weapons Case Advisory Opinion  ICJ Rep 226.
 UN Doc S/RES/1540 (2004) adopted 28 April 2004.
 According to Beck, no state is known to ship ready-made WMDs. Rather it is the components, technologies and production materials associated with WMDs that are shipped. M Beck, ‘The Promise and Limits of the PSI’ (2004) 10 The Monitor 16 <http://www.uga.edu/cits/documents/pdf/monitor/monitor_sp_2004.pdf> .
 Statement of Interdiction Principles, above n 73.
 Comprehensive Nuclear Test Ban Treaty (10 December 1996) ATNIA 13 May 1998.
 K Kasahara, ‘Hiroshima mayor lambasts US over new arms race’ Sydney Morning Herald (7-8 August 2004).
 A Prosser, ‘The Proliferation Security Initiative in Perspective’ <http://www.cdi.org/pdfs/psi.pdf> .