In response to Ukraine’s memorial of 22 May 2020, the Russian Federation raised preliminary objections of which a central claim was that the dispute concerns military activities which are excluded from the Arbitral Tribunal’s jurisdiction under Article 298(1)(b) of the United Nations Convention on the Law of the Sea (LOSC). Notably, the Russian Federation made the same preliminary objection in the Dispute Concerning Coastal State Rights. At the same time, Ukraine claimed in its memorial that the Kerch Strait incident concerned law enforcement measures that are not excluded from the jurisdiction of the Annex VII Arbitral Tribunal.
“After being held for about eight hours, the Ukrainian naval vessels apparently gave up their mission to pass through the strait and turned around and sailed away from it. The Russian Coast Guard then ordered them to stop and, when the vessels ignored the order and continued their navigation, started chasing them. It was at this moment and in this context that the Russian Coast Guard used force, first firing warning shots and then targeted shots. One vessel was damaged, servicemen were injured and the vessels were stopped and arrested. /…/ [W]hat occurred appears to be the use of force in the context of a law enforcement operation rather than a military operation.” (paras. 73-74)
The Annex VII Arbitral Tribunal found in its recent Award on preliminary objections that the aftermath of the Kerch Strait incident, i.e., the continued detention of the vessels and their crews and the prosecution of the Ukrainian servicemen did not concern military activities (para. 124). However, different from the ITLOS’ preliminary assessment of the Kerch Strait incident three years ago, the Arbitral Tribunal found that most other episodes in the Kerch Strait incident concerned military activities, at least until the point when the Russian Federation ordered the Ukrainian ships to stop. The Annex VII Arbitral Tribunal did not decide yet whether the order to stop and the boarding of Ukrainian naval ships and the arrest of the crew constituted military activities. The determination of the precise point at which the events ceased to be “military activities” was postponed to the merits phase (para. 208).
Did the Kerch Strait Incident amount to an Armed Conflict?
In the Kerch Strait incident, the armed groups included on the Ukrainian side two warships and a naval tugboat that were targeted and detained in a Russian operation that, according to the Russian Federation’s own accounts (paras. 2, 37, 43), involved in total ten naval warships and Coast Guard ships and a Russian combat helicopter. At the same time, the Russian fighter jets patrolled the Kerch Strait. The Arbitral Tribunal concluded in its recent Award on preliminary objections in relation the first phase of the Kerch Strait incident that “the Russian vessels were confronting the naval vessels of another State that had refused to obey an order relating to transit within its territorial sea.” (para. 118)
Ukraine pointed out in its submissions to the Arbitral Tribunal on the Preliminary Objections of the Russian Federation that its ships, including its warship Berdyansk, “never engaged with the Russian coast guard (or military)” and that they “took overt measures to demonstrate their arms were not being used or deployed” as they were “peacefully leaving an area” after abandoning the plan to transit the Kerch Strait and “not arrayed in opposition” to the Russian Federation’s ships that were at the same time using force against the Ukrainian warships (paras. 39-41). However, in its recent Award on preliminary objections, the Annex VII Arbitral Tribunal found that:
“The Ukrainian vessels remained in that anchorage area for approximately eight hours surrounded by Russian vessels and with Russian military helicopters flying overhead. At some time during this period, the guns of the Berdyansk were raised to a 45–50 degree angle. /…/ Raising and lowering guns may well have been an attempt to limit any confrontation, but at the same time, in the view of the Arbitral Tribunal, it is indicative of the fact that the Ukrainian vessels perceived themselves as being in a confrontation with the naval vessels of the Russian Federation.” (paras. 114, 116)
Ukraine’s description of the events in the Kerch Strait incident as presented to the Annex VII Arbitral Tribunal were in contrast with Ukraine’s earlier claims to the UN according to which the Russian Federation’s actions in the Kerch Strait incident “constitute an act of armed aggression… undermining the peaceful settlement of the Ukrainian-Russian armed conflict”. In the current arbitral proceedings, the Arbitral Tribunal took note of these earlier announcements and stated that:
“The Arbitral Tribunal is not suggesting that an estoppel against Ukraine arises from the words it used before the Security Council, or that Ukraine’s words should be characterized as statements against interest. Ukraine’s statements before the Security Council are simply an indication of how at that time Ukraine understood and characterized the events. Equally, Ukraine’s request that the detained servicemen be treated as prisoners of war is a further indication that at the time Ukraine perceived the confrontation to have been a military one.” (para. 117)
In the Kerch Strait incident, the Ukrainian Navy did not fight back when the Russian Federation used force against its ships. This has relevance for assessing the intensity of fighting. Yet reciprocity in fighting is not a precondition for the aggressor State’s use of force to be qualified as an armed attack triggering the right of self-defence of the targeted State. For example, should a tactical nuclear weapon be used in a surprise attack against a foreign warship, then it would clearly meet the criteria of an armed attack and trigger an international armed conflict between the two States even if the ‘deterrence’ has such an effect on the targeted State that it does not respond militarily. Heintschel von Heinegg has noted that (at p. 452) in recent State practice, the 2010 torpedo attack against the South Korean warship Cheonan has been qualified as an armed conflict even though South Korea did not respond to the attack that was predominantly associated with North Korea.
The Boarding and Arrest of the Ukrainian Warships – A Military Activity or Law Enforcement?
The Annex VII Arbitral Tribunal postponed its decision on whether the second phase of the Kerch Strait incident constituted military activities. According to the Award, the second phase started with the Russian order to stop that was issued to the Ukrainian ships and continued until the boarding of Ukraine’s ships and the arrest of the crew (para. 123). In its recent Award on preliminary objections, the Arbitral Tribunal maintained that:
“Two possibilities present themselves in this phase. One is that, at the point when the Ukrainian vessels began to leave the territorial sea in order to return to Odesa, the actions of the Russian vessels took on a law enforcement character. At that point, there would have been an end to military activities. The alternative possibility is that it was the boarding and arrest of the Ukrainian vessels that brought the confrontation between the vessels of the two States, and thus the military activities, to an end. The Arbitral Tribunal needs further elucidation of this matter by the Parties before reaching a conclusion and thus postpones that decision to the merits.” (para. 123)
It remains to be seen what weight, if any at all, the Annex VII Arbitral Tribunal puts on the fact that the Russian Coast Guard (instead of its warships, including a corvette, that were also involved in the operation) detained the Ukrainian warships in the Kerch Strait incident. According to Article 3(d) of the UN General Assembly Resolution 3314 Definition of Aggression, an act of aggression includes, inter alia, an attack by the armed forces of a State on the land, sea or air forces, or marine and air fleets of another State. The reference to the ‘armed forces of a State’ in the said provision of the Definition of Aggression may potentially also include a State’s Coast Guard. Notably, as pointed out by the Russian Federation in its preliminary objections (para. 40), its Coast Guard, similarly to that of many other major maritime powers, is closely intertwined with its Navy.
The line between the activities of warships and law enforcement vessels has become blurred. Under the domestic legal frameworks of various coastal States, warships are used for various law enforcement functions, including search and rescue, disaster relief, prevention and elimination of ship-based marine pollution, peacetime countermine operations, etc. The Kerch Strait incident demonstrates that Coast Guard vessels can be equally effectively employed to use force against foreign warships.
Against this background, the ITLOS observed in its Order of 2019 (at para. 64) that “the traditional distinction between naval vessels and law enforcement vessels in terms of their roles has become considerably blurred /…/ and it is not uncommon today for States to employ the two types of vessels collaboratively for diverse maritime tasks.” The Annex VII Arbitral Tribunal reached in its Award on preliminary objections in the Dispute Concerning Coastal State Rights a similar conclusion: “Forces that some governments treat as civilian or law enforcement forces may be designated as military by others, even though they may undertake comparable tasks.” (para. 335) The ITLOS explained in its Order of 2019 (at paras. 65-66) further that:
“Nor can the distinction between military and law enforcement activities be based solely on the characterization of the activities in question by the parties to a dispute. This may be a relevant factor, especially in case of the party invoking the military activities exception. However, such characterization may be subjective and at variance with the actual conduct. In the view of the Tribunal, the distinction between military and law enforcement activities must be based primarily on an objective evaluation of the nature of the activities in question, taking into account the relevant circumstances in each case.”
It is widely understood that the distinction between the law enforcement and humanitarian law paradigms does not depend on whether the activities were carried out by the military (armed forces in a strict sense) or law enforcement officials (see, e.g. Gaggioli at p. 12). This is particularly important in the context of hybrid warfare as it demonstrates that the classification of an aggression is based on the actual merits of the incident, not its form. By comparison, as Gill and Fleck note (at p. 64), law enforcement operations can equally be conducted by the military or civilian State agents:
“The concept of law enforcement could thus be said to comprise all measures taken by civilian or military State agents to maintain, restore, or impose public security, law, and order or to otherwise exercise its authority or power over individuals, objects, or territory.”
Gill and Fleck conclude that: “As a matter of generic concept, therefore, law enforcement and military hostilities are not mutually exclusive, but may overlap considerably.” (ib., at p. 65) For example, as Fink has explained (at p. 194), what initially was planned as a law enforcement operation may in practice gradually develop to a situation of naval warfare. In practice, such escalation of a maritime incident was evident in the conflict between the Russian Federation’s Coast Guard and Ukrainian warships in the Kerch Strait.
In its recent Award on preliminary objections, the Annex VII Arbitral Tribunal made it clear that a naval incident may also, from a legal perspective, gradually de-escalate from a military activities paradigm to one of law enforcement. Distinct from the ITLOS’ Order for the prescription of provisional measures in relation to the Kerch Strait incident in which the ITLOS made the preliminary assessment that the incident was a law enforcement operation rather than a military operation (para. 74), the Arbitral Tribunal rejected in its recent Award on preliminary objections “the rigid “either-or” proposition” and found that “activities that initially have a law enforcement character may become activities with a military character, and vice versa.” (para 121)
Comparison with the Guyana v. Suriname case
The enforcement of the Russian Federation’s domestic rules on passage through the Kerch Strait eventually resulted in the use of arms against the Ukrainian warships and their detention along with crew. It has been argued that the primary criteria for the differentiation between the law enforcement and armed conflict paradigms are ‘the status, function or conduct of the person against whom force may be used’ (see Gaggioli at p. 59, Gill and Fleck at p. 79). In this context, the use of force by a State against the warships of another State, as in the case of the Kerch Strait incident, falls prima facie within the framework of military operations paradigm.
For comparing the conclusions of the Annex VII Arbitral Tribunal in its recent Award on preliminary objections with its previous case law, the Award in the Guyana v. Suriname case is particularly useful. In their dispute before the Annex VII Arbitral Tribunal, both Ukraine and the Russian Federation made surprisingly scarce references to the Guyana v. Suriname arbitration.
Yet the two disputes have considerable overlap as they concern incidents that occurred in a disputed maritime area and that one of the parties to the dispute characterises as a law enforcement measure, whereas the other party claims that the relevant incident concerned military activities. In the Kerch Strait incident, force was actually used by one State against the warships of another State: targeted shots caused casualties among the servicemen and the shots as well as ramming resulted in material damages to the Ukrainian warships.
Based on the comparison between the two incidents, it is fair to say that the Russian Federation’s measures against the Ukrainian warships in the Kerch Strait incident exceeded the limits of a mere law enforcement operation. If the warnings issued from the Surinamese warships to a private person constituted a military activity partly due to the disagreements between Guyana and Suriname over the title to the relevant maritime area, then actual use of force against warships in a disputed maritime area in the wider framework of a prolonged armed conflict between the relevant two States should presumably also be deemed as falling under the jus ad bellum and jus in bello framework.
Furthermore, the test applied by the Annex VII Arbitral Tribunal in the Guyana v. Suriname case for determining whether the measures used by Suriname fell under the law enforcement paradigm or amounted to a military activity involved to a significant level the subjective element which was combined with the ex post objective assessment by the Tribunal. The Tribunal explicitly put emphasis in its categorisation of the incident as falling outside the scope of law enforcement measures on the victim State’s and private persons’ subjective perspective according to which they felt themselves as being threatened by the use of force, although the other Party to the conflict strongly denied in the judicial proceedings that it had any intention to resort to the use of force.
Different from the ITLOS’ Order for the prescription of provisional measures in relation to the Kerch Strait incident in which the ITLOS categorised the incident as a law enforcement operation rather than a military operation, the Annex VII Arbitral Tribunal found in its recent Award that most of the episodes in the Kerch Strait incident concerned military activities. In the view of the present author, it is possible that the Kerch Strait incident reached the threshold of an armed attack given that it (different from the circumstances of, e.g., the M/V Saiga Case and the Guyana v. Suriname Case) involved the existence of two conflicting organized armed groups that were engaged in fighting of some intensity as illustrated by the exchange of fire and casualties among the crew of the Ukrainian Navy.