How Does Belligerent Occupation End? Some Reflections on the Future of the Territories Occupied in the Russia-Ukraine Conflict

Keywords: belligerent occupation – armed conflict – end – peace – Ukraine – Russia.
 

In the past months, news outlets have extensively reported on Ukraine’s more or less effective counter-offensive, as well as on renewed rumours of possible negotiations between Ukraine and Russia.[1] Given the latter’s annexation of several Ukrainian regions in September 2022,[2] these reports clearly raise the question of the future of these and other occupied territories.

While this question may be addressed through the lens of various rules of international law – e.g., the prohibition on the use of force, the principle of territorial integrity, and the duty of non-recognition as lawful of situations resulting from grave breaches of peremptory norms, including that prohibiting aggression –, the present investigation seeks to address it primarily through the prism of relevant rules of international humanitarian law (hereinafter IHL). Thus, after briefly recalling the conditions for the beginning of a belligerent occupation under IHL, the focus will shift on those for its termination, which will be examined and discussed with reference to the case of Ukraine.

As is well known, belligerent occupation consists in the exercise of effective control over (part of) the territory of a State by one or more other States without the former’s consent.[3]  In other words, for a belligerent occupation to begin and relevant IHL rules to apply, the foreign troops’ presence within a State’s territory must not only amount to the exercise of so-called effective control, but also be hostile.

As far as the first requirement is concerned – i.e., the exercise of effective control –, this expression is generally meant to describe the fulfilment of the following cumulative conditions: (a) foreign troops are present within a State’s territory; (b) these troops are able “to exercise authority over the areas [in question] in lieu of the territorial sovereign”; and (c) the ousted government is unable to exercise its authority over these areas.[4] The notion of “authority” clearly refers to the exercise of governmental functions through the establishment of a temporary administration over the territory in question.[5] However, in the present writer’s view, even the mere ability to exercise authority (so-called “potential control”) would suffice.[6] Thus, occupation law begins to apply once the occupier has ousted the legitimate sovereign and is in a position to exercise its own authority over the territory in question.

As for the second requirement – i.e., the hostile nature of the foreign troops’ presence –, this stems from the wording of art. 42 of the Hague Regulations: occupation law only applies when a “hostile army” occupies part or whole of a State’s territory. Since common art. 2(2) clearly states that occupation law applies even in the absence of any armed resistance, the hostile nature of an occupation admittedly derives from lack of consent. In other words, military occupation is belligerent only when it is unconsented-to; if consent is given, occupation law does not apply.[7] However, for consent to exclude the hostile nature of an occupation, certain conditions must be met: first, said consent must be valid – i.e., given by an agent or person authorised to do so on behalf of the State, and given without coercion, error, fraud or corruption;[8] second, it must be given explicitly;[9] third, the occupying troops’ conduct must remain within the limits of the consent received.[10]

Once a belligerent occupation is established, determining when it ends also depends on the assessment of the abovementioned requirements, i.e., exercise of effective control and hostile nature of the foreign troops’ presence.

As far as the first one is concerned, it is widely accepted that, whenever the occupier ceases to exercise effective control over the territory in question, belligerent occupation ends.[11] This may happen by way of either a military withdrawal or a resumption of fighting. In the former case, the occupier itself may choose to withdraw (so-called “unilateral withdrawal”) or an agreement may so establish (so-called “negotiated withdrawal”).[12] In the latter case, active hostilities with the occupied State’s armed forces or with a resistance movement may resume.

As for the requirement of the hostile nature of the occupation, this may cease to apply when either the authorities of the occupied State validly consent to the continued presence of foreign troops[13] or a change in status of the territory in question is established by an agreement[14] or by the exercise of the right to self-determination of the people inhabiting said territory.[15]

Clearly, when it comes to several of the outcomes described above, some caution is warranted, as the analysis of the Ukrainian case will now show.

As things stand today, a significant portion of Ukrainian territory is currently or has recently been under Russian occupation, notably Crimea since 2014, the four regions that have been formally annexed by Russia in September 2022 (i.e., Luhansk, Donetsk, Kherson, and Zaporizhzhia), and some other border areas that were arguably occupied for more or less short periods of time right after Russia’s 2022 invasion.[16] Clearly, as active hostilities are ongoing and the situation on the ground is evolving rapidly, any attempt to draw final conclusions on the future status of these and other Ukrainian territories would be vain. What this paper seeks to offer instead is a brief analysis of possible scenarios in light of relevant IHL rules.

As mentioned above, occupation may end when the occupier ceases to exercise effective control. This seems to have already happened – to a limited extent – as a consequence of Ukraine’s recent counter-offensive. Indeed, Russian forces appear to have withdrawn from some of the territories previously held due to a resumption of hostilities.[17] However, it is to be noted that hostilities do not automatically result in the termination of a situation of occupation, as IHL rules, State practice, and domestic and international case-law all point to the existence of a presumption in favour of its continuance once effective control has been established and insofar as the abovementioned conditions for its exercise are met.[18] Indeed, a resumption of hostilities may not result in the termination of a belligerent occupation when they are sporadic and do not affect the ability of the occupier to exert its authority. Thus, in the case of Ukraine, while some areas certainly appear to have returned under Ukrainian control, the same may not be true for other areas where intense fighting is currently taking place. The fact that, in those areas, Russian forces are engaged in active hostilities does not necessarily mean that their status as occupying forces and the powers and duties that come with it have ceased. Insofar as these troops are still able to exercise a level of control over the territories in question in spite of the resumption of hostilities and as long as their authority is not substituted by Ukraine’s authority, the situation of occupation persists.[19]

It has also been previously mentioned that a belligerent occupation may end when its nature is no longer hostile. In the case of Crimea and the other regions that were annexed by Russia, the question arises as to whether the referendums held in those territories – by which the majority of the inhabitants voted in favour of the incorporation into Russia[20] – amount to an expression of the valid and genuine will of a people that is entitled to the right to self-determination under international law. In the present writer’s view, this is not the case for several reasons. Suffice it to mention that, first, none of the territories in question had been “pacified” prior to the holding of the referendums.[21] As the Brazilian delegate in the UN Security Council clearly put it after the 2022 ones, “[i]t is unreasonable to assume that populations in areas of conflict are able to freely express their will”.[22] Second, relevant IHL rules clearly exclude similar alterations to the status of the occupied territory: belligerent occupation is meant to be temporary, and does not entail any transfer of sovereignty to the occupier.[23] Third, even assuming that in principle the exercise of the right to self-determination could justify a violation of the territorial integrity of a State by another State,[24] in the case at hand the populations concerned do not appear to be peoples entitled to self-determination under current international law, as the scope of application of this right is limited ratione personae to peoples fighting against colonial domination, racist regimes, or foreign occupation.[25] In light of the above, it may come as no surprise that the invalidity of the referendums held in 2014 and 2022, and of the ensuing annexations, has been declared by a (more or less) large majority within the UN General Assembly.[26]

It is finally worth recalling that belligerent occupation may also end by the conclusion of an agreement between the authorities of the occupied State and the occupier resulting in the transfer of sovereignty over the occupied territories.[27] This is one of the potential outcomes of the Russia-Ukraine conflict that have been debated since the first months of the 2022 invasion. However, the validity of a similar agreement under international law would be questionable. Suffice it to mention that, under art. 52 of the Vienna Convention on the Law of Treaties (VCLT), “[a] treaty is void if its conclusion has been procured by the threat or use of force”. Clearly, this does not mean that any peace agreement would be void. Only an agreement procured by the use of force would be. In other words, while a peace agreement regulating the end of the conflict without “leaving the aggressor any unjust advantage” would be valid, one “aimed at reserving to an aggressor the fruits of his illegal attack” would be void.[28] This interpretation of art. 52 VCLT appears to be confirmed by art. 75 VCLT, which clarifies that the latter is “without prejudice to any obligation in relation to a treaty which may arise for an aggressor State in consequence of measures taken in conformity with the Charter of the United Nations with reference to that State’s aggression”.[29] Furthermore, given the peremptory nature of the prohibition of aggression, the invalidity of any peace agreement benefitting the aggressor would also stem from its “conflict with a peremptory norm of general international law”.[30]

In the final analysis, while a negotiated end to the occupation of Ukrainian territories may certainly seem appealing, some caution is required when it comes to determining the content of such an agreement in light of relevant rules on international law. Caution is also warranted in respect of other potential endings to the situation of occupation, i.e., a resumption of hostilities in the occupied territory and the (alleged) exercise of the right to self-determination.