Ukraine Insta-Symposium: When does the Breach of a Status of Forces Agreement amount to an Act of Aggression? The Case of Ukraine and the Black Sea Fleet SOFA

Ukraine Insta-Symposium: When does the Breach of a Status of Forces Agreement amount to an Act of Aggression? The Case of Ukraine and the Black Sea Fleet SOFA

[Dr. Aurel Sari is a Lecturer in Law at the University of Exeter.]

Over the last few days, a growing number of commentators and international actors have denounced the deployment of Russian troops in Crimea not simply as a violation of the sovereignty and territorial integrity of the Ukraine, but as an act of aggression. At its extraordinary meeting held on 3 March 2014, the Council of the European Union condemned “the clear violation of Ukraine’s sovereignty and territorial integrity by acts of aggression by the Russian armed forces”. On 4 March 2014, United States Secretary of State John Kerry followed suit at a press briefing held at the US Embassy in Kiev.

A prima facie case of aggression

Assuming for the sake of argument that the activities of Russian armed forces in Crimea do not benefit from the valid consent of the Ukraine (the question is at least arguable: see here and here), a good case can indeed be made that their presence and conduct fits the archetypical example of aggression, namely the ‘invasion or attack by the armed forces of a State of the territory of another State’ as defined in Article 3(a) of United Nations General Assembly Resolution 3314 (XXIX) on the Definition of Aggression of 1974.

In so far as aggression is said to constitute ‘the most serious and dangerous form of the illegal use of force’ (Preamble, Definition of Aggression), the situation in Crimea must reach a certain threshold of gravity in order to qualify as an act of aggression. Neither the exact level of this threshold nor the facts on the ground are established beyond all reasonable doubt. However, it is safe to assume that the deployment of Russian forces to maintain public order in Crimea and to blockade and occupy Ukrainian military premises and assets in such a continuous and robust manner as we have seen in the last few days rises above the level of a ‘mere frontier incident’ or ‘less grave forms of the use of force’ (Nicaragua, paras 191 and 195). As such, these acts may reasonably be characterized as aggression on account of their scale and effects.

Article 3(e) of the Definition of Aggression

As reported earlier, the Ukrainian Association of International Law has come to the same conclusion in its recent appeal regarding the events in Crimea. Amongst other things, the Association suggests that the Russian Federation has committed an act of aggression as a result of being in material breach of the Agreement between Russia and Ukraine on the Status and Conditions of the Presence of the Russian Black Sea Fleet on the Territory of Ukraine of 8 of August 1997 (the Black Sea Fleet SOFA; see here in Russian). This argument raises an interesting question about the application of Article 3(e) of the Definition of Aggression. Pursuant to Article 3(e), the following acts shall constitute an act of aggression:

The use of armed forces of one State which are within the territory of another State with the agreement of the receiving State, in contravention of the conditions provided for in the agreement or any extension of their presence in such territory beyond the termination of the agreement.

Compared to some of the other acts listed in Article 3, the incidents envisaged under Article 3(e) of the Definition may appear relatively benign or even banal. Whereas an armed invasion, attack or bombardment will amount to an act of aggression only if it entails the use of force at a relatively high level of intensity, it seems that even a minor breach of a status of forces agreement could qualify as an act of aggression under Article 3(e) even if it causes no damage or destruction in the host State. Some commentators have therefore questioned whether Article 3(e) should have been included in the Definition at all.

The importance of contextual interpretation

State practice offers a number of examples where foreign armed forces are present abroad without the consent of the territorial State or another valid legal basis, yet their presence does not come within the Definition of Aggression. A case in point is the accidental ‘invasion’ of Liechtenstein by 170 Swiss troops who got lost in a military exercise in 2007. No one, it seems, has suggested that Switzerland has committed an act of aggression against Liechtenstein, despite the fact that this was not the first such intrusion. Despite the strict terms of Article 3(e), it seems that context is everything.

This point was certainly not lost on the drafters of the Definition of Aggression. The Six Power draft submitted on 25 March 1969 by the Australia, Canada, Italy, Japan, the United States and the United Kingdom defined aggression with reference to a prohibited purpose, thus giving rise to protracted debates as to whether the presence of an ‘animus aggressionis’ was a necessary element of aggression (see UN Doc A/7620). Eventually, any express references to aggressive intent were removed from the Definition. However, an implicit reference to intent was retained in Article 2 of the Definition, which declares that the Security Council may conclude that determining the prima facie existence of an act of aggression would not be justified ‘in the light of other relevant circumstances, including the fact that the acts concerned or their consequences are not of sufficient gravity.’ Although Article 2 is specifically addressed to the Security Council, Article 3 declares that it must be applied ‘subject to and in accordance with the provisions of article 2’. This point is further underlined by Article 8 of the Definition, which provides that ‘[i]n their interpretation and application the above provisions are interrelated and each provision should be construed in the context of the other provisions.’

Accordingly, not only does Article 2 of the Definition of Aggression provide room for contextual interpretation, but it appears that this contextual approach applies across the board and not just to the Security Council. It is worth mentioning in this respect that in Nicaragua the ICJ accepted that the circumstances and possible motivations of the use of force play a role in its legal characterization (Nicaragua, para. 231).

The need for a material breach

The foregoing confirms what common sense already suggests, namely that a simple violation of an agreement governing the conditions of the presence of foreign armed forces does not, in and of itself, automatically amount to an act of aggression under Article 3(e) of the Definition of Aggression. Rather, as in the case of the other acts enumerated in Article 3, the acts in question must cross a certain threshold of gravity before they qualify. This reading finds support in the actual terms of Article 3(e), which refers to the ‘use of armed forces of one State’ in contravention of the agreement regulating their presence in the territory of another State. It is therefore the active use of those forces, rather than their mere passive presence, which is addressed in Article 3(e).

Returning to the Ukrainian Association of International Law, it is interesting to note that it skilfully characterizes the deployment of Russian troops in Crimea as a ‘material breach’ of the Black Sea Fleet SOFA. Article 60(3)(b) of the Vienna Convention on the Law of Treaties defines ‘material breach’ as the violation of a provision essential to the accomplishment of the object or purpose of the treaty (not to be confused with the requirement of a ‘manifest violation’ of the UN Charter for the purposes of the crime of aggression). Can we establish the existence of such a material breach in the present case?

According to Article 1 of the Black Sea Fleet SOFA, its purpose is to define the status of the Black Sea Fleet of the Russian Federation stationed on the territory of Ukraine. As Article 2 of the SOFA makes clear, the Agreement applies to Russian military formations and units forming part of or attached to the Black Sea Fleet only. Consequently, Russian armed forces not forming part of or attached to the Black Sea Fleet are not covered by the Agreement and their deployment into Crimea is not a breach, material or otherwise, of the SOFA. Of course, this does not mean that their deployment may not be a breach of other rules of international law, including the UN Charter. The point is simply that Article 3(e) of the Definition of Aggression is engaged in the present circumstances only if Russian units and formations belonging to the Black Sea Fleet, but not others, were to act in contravention of the SOFA.

Assuming for the sake of this analysis that units and formations belonging to the Black Sea Fleet were deployed in the Crimea during recent days, their activities would almost certainly be in breach of Article 6(1) of the SOFA, which requires Russian forces to respect the sovereignty and legislation of Ukraine and to refrain from interfering in its internal affairs; Article 8(2), which restricts Russian forces to carrying out manoeuvres and exercises within the areas agreed to by the Ukrainian authorities; Article 8(4), which entitles Russian forces to adopt protective measures only in consultation with the competent Ukrainian authorities; and Article 15(5), which stipulates that travel by Russian forces outside their agreed places of stationing is to be conducted following consultation with the Ukrainian authorities.

The common aspect of all of these breaches is that they contravene the restrictions placed on the freedom of movement of Russian forces and the nature and purpose of their activities in the Ukraine. Both of these aspects may reasonably be described not only as ‘essential to the effective execution of the treaty’, but as elements touching upon the central purposes of the SOFA (see here at 75) . Indeed, one of the main purposes of status of forces agreements as a specialized instrument of international law is to define the terms and conditions under which foreign forces may operate in the territory of the host State.

Accordingly, a strong case can indeed be made that the Russian Federation is in material breach of the Black Sea Fleet SOFA and as such is responsible for committing an act of aggression within the meaning of Article 3(e) of the Definition of Aggression.

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Aurel: The material breach of the bilateral agreement allows Ukraine (over at EJIL I have been reminded to not place the word “the” before Ukraine) to terminate the treaty and then to request Russian military to leave.  If thereafter they do not leave, there would be a compounding of breaches (of the SOFA and UN art. 2(4)) and aggression.
However, Article 3 of the 1974 Declaration on Aggression has a limitation regarding all of the listed conduct — “subject to and in accordance with the provisions of Article 2” — and Article 2 contains an overriding limitation: “in contravention of the Charter.”  Therefore, conduct must be violative of the U.N. Charter (e.g., of art. 2(4)).  That is why some breaches of SOFAs would not amount to acts of aggression.
And let us not forget that non-state actor armed attacks and uses of armed force against Ukraine can be attributable to Russia whether or not Russia has effective control of the non-state actors if there is “substantial involvement” by Russia. See ICJ (Nic. v. US); Dec. Aggression, art. 3(g);  (despite the fact that some textwriters use the wrong test for imputation re: self-defense).

Aurel Sari

Jordan, thanks for the comments. I don’t think that the limitation ‘in contravention of the Charter’ adds much for our purposes. The point of that qualification is simply to recognize that there could be instances where the first use of armed force does not qualify as an act of aggression because it is in accordance with the Charter, as in the case of force used or authorized by the Security Council. Since aggression is a specific form of the use of force (particularly grave and illegal), it follows that it must rise to the level of the use of force and, in principle, graviate towards the higher end of the spectrum. The trouble is that not every use of force involves kinetic operations (think training contras, as per Nicaragua) or even large-scale damage and destruction (think military invasion/occupation meeting no resistance). Morever, while we would normally expect an armed attack to involve kinetic and large-scale destructive effects, this does not necessarily have to be so (think use of chemical weapons without kinetic effect or invasion/occupation without resistance again). So, the level of damage or destruction caused by a particular use of force cannot be the sole factor in determining whether… Read more »

Aurel Sari

One more thought. What a material breach of a SOFA establishes is such a disregard for the underlying conditions on which the host State’s consent to the presence of foreign forces is based as to call into question that consent itself. Consequently, a material breach of the SOFA may, depending on the circumstances, transform the consensual presence of foreign forces into a non-consensual one, and this is really the point at which it starts to make sense describing a violation of a SOFA as an act of aggression.

Ian Henderson
Ian Henderson

Very interesting post about the role of SOAFAs, thanks. My Russian is a little rusty — is the SOFA a treaty or of less-than-treaty status? In any event, does it make any difference to your analysis?

Aurel Sari

Ian, I cannot comment on the SOFA’s standing in Russian or Ukrainian law, but from an international law perspective it sure is a full-blown treaty. In fact, it does not differ much from agreements adopted for similar contexts (ie stationing type SOFAs).


Aurel: I agree with Harold Koh and others, and the U.S. position, that there is no gravity threshold regarding armed force that violates Article 2(4) or triggers Article 51.  See footnote in the article at SSRN in the first response above.


[…] 6 March 2014 Aurel Sari at Opinio Juris (examines Russia’s action in the light of UNGA Resolution 3314 (XXIX) on the Definition of […]


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