1 Introduction
This paper examines how we should justify the practice of maritime interception operations (mio) on the high seas against suspected ships sailing under foreign flags, which have been conducted as a part of the War on Terror after 9/11.
Some states and scholars have advocated an expansive interpretation of self-defence for a sweeping legal basis for mio, in cases where the other rules such as the law of armed conflict including prize law or peacetime law of the sea do not give a legal ground or those are inapplicable.
However, the conclusion here is that such an approach is invalid and unnecessary, at least now. Also, from a policy perspective, it is inadvisable for maintaining the free and open maritime order in the 2020s.
2 Definition
Since 2001, there has been strong advocacy for the expansionist theory of self-defense. In this paper, this âexpansionist theoryâ is defined as a tendency to argue;
- 1.Self-defense against a non-state armed group in the territory of another state is legally permissible;
- 2.This is the case, even if the territorial state does not effectively control such group but may have failed to constrain the groupâs function due to negligence, unwillingness or incapacity; and
- 3.Necessity and proportionality are measured against the threat by the group, but it is done in a concertina-like quality that is flexibly manipulatable.1
Based on this single conjunction âor,â it was claimed that the United States could use force for self-defense without being part of an armed conflict. Consequently, under this theory, both the resort to armed force and the execution of specific operations shall be regulated by the jus ad bellum only, precluding jus in bello assessment and strict regulation for the use of force based on human rights law. In short, this approach produces a legal blackhole where neither human rights law nor the law of armed conflict applies.
3 Expansionist Theory at Sea: Legal Ground for mio?
This expansive interpretation of the right of self-defense was also asserted in the maritime domain for justifying mio widely.
As to the maritime interception in the initial phase of the War on Terror, Captain OâRourke, of the US Navy, advised that âArticle 51 of the UN Charter has come to be accepted as the primary basis for such operations.â3 The problem is whether this applied long after the immediate terrorist threat ceased. The revisionist says it is possible.
Indeed, we can find the self-defense justification for mio in US military doctrines, like the 2007 Commanderâs Handbook.4
4.4.4.1.9 Inherent Right of Self-Defense
States can legally conduct mio Pursuant to customary international law under circumstances that would permit the exercise of the inherent right of individual and collective self-defense.
This paragraph looks straightforward, but reading in conjunction with the other justifications listed here its meaning is unclear. Notably, the relationship between belligerent rights and this self-defense argument is ambiguous.
States could act against non-state actors on board foreign-flagged vessels under the limited circumstances that a flag State is unable or unwilling to act in order to remedy the situation, for instance in cases of vessels carrying wmd. â¦, the doctrine is tempting because ⦠it allows for the boarding of a foreign-flagged vessel without any form of consent of the flag State â¦7
He additionally pointed out that it could bypass the controversial legal question of whether the law of naval warfare applies in non-international armed conflict.
Under this revisionist self-defense approach, the mio started in the context of International Armed Conflict may be legal, regardless of whether the conflict classification changed afterwards, like Operation Enduring Freedom. This point may be the one to which this camp of the debate wanted to push the envelope. Here is the reason. The War on Terror is classified as a non-international armed conflict, where the law of naval warfare has been underdeveloped, or it is executed in a legal grey zone where the applicable rules are shaky. Therefore,
However, we should pay attention to the same documents recently being updated with more nuance. The 2017 edition of the Commanderâs Handbook had two additions to the previous edition.8
4.4.4.1.8 Inherent Right of Self-Defense
States can legally conduct maritime interception operations pursuant to customary international law under circumstances that would permit the exercise of the inherent right of individual, collective, and national self-defense as recognized in Article 51 of the United Nations Charter. (emphasis added)
The first is the term ânational self-defense,â and the second is the phrase âas recognized in Article 51 of the United Nations Charter.â The text itself does not clarify the intention of this new paragraph. Still, it is safe to say that the emphasis on national self-defense and Article 51 of the UN Charter would not go along with the revisionist campâs direction.
Professor Heintschel von Heinegg also took a more nuanced position in his comment on the 2015 edition of the same Operation Law Handbook, substantially limiting his statement in the previous edition: âStates merely agree on the principal applicability of the right of self-defence as a legal basis for mio. There is no agreement as to the specific measures that may be taken against suspect vessels and persons on board.â9
4 âEmbracing the Uncertainty of Oldâ?
The next point is that such assertion of a self-defense plea is not novel. Christian Tams pointed out, âWhether States can use force in self-defence
The same applies to the maritime sphere. Professors Churchill and Lowe introduced Statesâ attempt to advocate exceptional measures to interfere with foreign ships on the high seas on the grounds of self-defense with some examples.
The first and most referenced one is the Virginius incident of 1873. There, Spain seized on the high seas an American ship carrying American and British nationals and many weapons for use in the Cuban insurrection. Great Britain accepted that the arrest was justified on the ground of self-defense, while the United States did not. Some scholars refer to this case as supportive evidence for the self-defense argument. However, the reality is that this British reaction was isolated and firmly opposed.11 Professor Gidel concluded that this was âprétendument reconnu (pretended to be recognized).â12
The evidence of state practice and opinio juris generated by opposition to the French policy would still seem to militate against the existence of any extended right of self-defense against weapons shipments on the high seas.13
However, in fact, all these debates have been already settled in the past. The International Law Commission, 1956, in a discussion of the High Sea Convention, considered the right to board a vessel committing hostile acts to the intervening State at a time of imminent danger. The Commission did not recognize it, mainly because of the vagueness of terms like âimminent dangerâ and âhostile actsâ that are open to abuse.14
self-defence or national security is an insecure foundation for seeking to qualify the freedom of the seas, for it could lend plausibility to restraints that would not sustain the balance of interests of the international community.15
State practice before 2001 shows that there was no overall acceptance of the self-defense exception to the exclusive flag States jurisdiction for the vessels on the high seas.
5 Emerging Self-Defense Justification for mios?
The mio has, through accepted practice and custom, developed a new legal regime under which ⦠warships may intercept foreign flag commercial vessels on the high seas, without resorting to any classical belligerent right. This expansion is now well established through over ten years of continuous, unchallenged operations.16
Professor Klein contrasts this new practice against the previous one with far less acceptance.17
However, careful examination of the case overshadows such claims. From the outset, the participating states to the mio have different views on the legal basis for the operation. Captain OâRourke qualified his assertion that the right of self-defense is the primary basis for the mio by saying that âas time passes, the question will loom larger.â He seems to believe in a customary rule permitting the continuance of the mio. However, his conclusion to this question was, âOnly time will tell.â18
Although maritime units may use force such as is necessary and proportional, they may be required to do so within the peacetime rules and conventions which apply at sea. ⦠The UK is simply not prepared to invoke the right of self-defence for such boardings without seeking flag state approval.19
This position was also reflected in an operational manoeuvre. In Operation Active Endeavour, which lasted until 2016 in the Mediterranean Sea, the mio was declared an Article 5, collective self-defense operation, of the nato Treaty. However, in reality, the boarding took place only when both flag State and the master consented. As Professor Heintschel von Heinegg admitted, âThe practice of those States whose navies have taken part in counter-terrorism operations at sea is quite diverse and has not contributed to the emergence of agreed-upon criteria. This explains the importance of other rights of maritime interception.â20
Additionally, based on research of the national manuals collected by the Stockton Center, it is revealed that recent manuals (Denmark 2020, New Zealand 2019) have maintained the clear bifurcated structure of naval warfare based on the law of armed conflict, including the San Remo Manual on the one hand and maritime law enforcement regulated by the unclos on the other hand. There is no indication of overarching justification of self-defense for mios.
The reality is that even the states advocating the self-defense argument obscured their position, trying to secure the alternative ways, such as a bilateral agreement with or ad hoc consent of the flag States. On the other hand, opposition states make a clear statement against such an approach. These could not be an indication of the recognition of a new customary rule.
6
Even if this sweeping justification by self-defense is attractive for operational purposes, this paper concludes that it is unnecessary and inadvisable, both from the normative and policy perspective.
Firstly, any claims based on self-defense are, in nature, insecure, provisional, and supplementary. Thus, at best, it could be a second-best basis only. When any alternative cause is available, that will fade from the front stage, remaining an exceptional measure.
Secondly, from a policy perspective, we should recall the conclusion of Professor OâConnell that self-defense would not sustain the balance of interests of the international community.
Admittedly, years just after 9/11, this balance of interests seemingly leaned towards the expansionist direction. However, twenty years after, we should readjust it to the point Professor OâConnell set. In the 2020s, we face other challenges affecting the balance of interests, such as hybrid warfare conducted at sea by sovereign states. Certain states can use hybrid warfare strategies to annoy law-abiding states by intentionally obscuring the legal nature of their actions. Blurring the clear bifurcation of the use of force paradigms would benefit such states the most.
A sweeping national security exception could pave the road to the hazardous attempts by states, ruining the cardinal principles of the Law of the Sea based on vague reasons, such as self-preservation or protection of sovereignty.
Nehal Bhuta and Rebecca Mignot-Mahdavi, âDangerous Proportions: Means and Ends in Non-Finite War,â asser research paper 2021-01, available at:
Harold Hongju Koh, âThe Role of the Legal Adviser,â Proceedings of American Society International Law, Vol.104 (2010), p. 207, pp. 219â220.
Kenneth OâRourke, âCommentary: Maritime and Coalition Operations,â in International Law and the War on Terror (International Law Series, Vol.79 (2003)), p. 297, p. 298.
US Navy, The Commanderâs Handbook on the Law of Naval Operations, nwp 1â14M, Edition July 2007, para. 4.4.4.1.9.
Rule 20.o9 âStates can legally conduct mio pursuant to customary international law under circumstances that would permit the exercise of the inherent right of individual and collective self-defense.â Wolff Heintschel von Heinegg, âChapter 20: Maritime Interception/Interdiction Operations,â Terry D. Gill and Dieter Fleck (eds.), The Handbook of the International Law of Military Operations (1st Edition) (Oxford University Press, 2010), p. 375, p. 389.
Id., p. 390.
Martin Fink, Maritime Interception and the Law of Naval Operations (Springer, 2018), pp. 118â119.
US Navy, The Commanderâs Handbook on the Law of Naval Operations, nwp 1â14M, Edition August 2017, para. 4.4.4.1.8.
Wolff Heintschel von Heinegg, âChapter 21: Maritime Interception/Interdiction Operations,â Terry D. Gill and Dieter Fleck (eds.), The Handbook of the International Law of Military Operations (2nd Edition) (Oxford University Press, 2015) p. 442, pp. 440â441.
Christian J. Tams, âEmbracing the Uncertainty of Old: Armed Attacks by Non-State Actors Prior to 9/11,â Zeitschrift für ausländisches öffentliches Recht und Völkerrecht, Vol.77 (2017), p. 61, pp. 61â64.
Kiara Neri, Lâemploi de la force en mer (Bruylant, 2013), p. 404.
Gilbert Gidel, Droit international public de la mer (Mellottée, 1932), t.1, p. 355.
Michael Byers, âPolicing the High Seas: The Proliferation Security Initiative,â American Journal of International Law, Vol.98 (2004), p. 526, p. 533.
Yearbook of the International Law Commission, 1956, Vol.2. p. 284.
Daniel Patrick OâConnell (Ivan Shearer ed.), The International Law of the Sea, Vol. ii, 1st ed. (Clarendon Press, 1988) p. 797.
The Defense Institute of International Legal Studies (diils), Maritime interception operations, 13 June 2005, cited in Fink, op.cit., p. 120.
Natalie Klein, Maritime Security and the Law of the Sea (Oxford University Press, 2010), p. 275.
OâRourke, op. cit., p. 298.
Neil Brown, âCommentary: Maritime and Coalition Operations,â in International Law and the War on Terror (International Law Series, Vol.79 (2003)), p. 303, p. 305. See also a Canadian military advisorâs comment (Jean-Guy Perron, âCommentary: Maritime and Coalition Operations,â in ibid., pp. 309â310).
Heintschel von Heinegg, op. cit. [2017].