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Is the Russian Annexation of Ukraine Actually Illegal?

Since February, a consensus has emerged: by its invasion of Ukraine the Russian Federation has ignored fundamental principles of international law. However, Russian President Vladimir Putin’s recent announcement of the annexation of the Ukrainian regions known as the Donbas (Luhansk and Donetsk), Zaporizhzhia, and Kherson has introduced a new legal question, namely whether international law allows one state, after invading the territory of another, to conduct referenda and annex that territory?

Both the NATO-aligned states and Putin have clear, opposing answers to that question. World leaders were quick to condemn the annexation, calling it a ‘complete farce’ that is ‘trampling on the United Nations Charter.’ Several also vowed to never recognise the territorial change. Citing the UN Charter, the Secretary-General of the United Nations claimed the annexation has ‘no legal value.’ News correspondents have been similarly critical, calling the annexation a ‘carbon copy’ of the disputed 2014 annexation of Crimea. On October 12th the international community adopted a UN General Assembly Resolution condemning the annexation after Russia vetoed a similar Security Council Resolution.

In response, Putin defended the annexation with two legal arguments. First, he claimed that Donetsk and Luhansk were independent ‘people’s republics,’ not Ukrainian territories. Second, claiming that the annexation was the ‘will of millions of people,’ Putin argued that the regions were exercising their right of self-determination (the right of individuals to establish or redefine a state of their territorial creation). According to Russian officials, 93% of voters supported the change in Zaporizhzhia, 89% in Kherson, 98% in Luhansk, and 99% in Donetsk. Western commentators have cast doubt on the validity of these results.

Despite their claims, the UN Charter is not the best support for either the West’s or Putin’s positions. While the UN Charter bans the use of force for reasons other than self-defence, it does not address annexation. Several commentators have pointed to Article 2(4): ‘all members shall refrain in their international relations from the threat or use of force against the territorial integrity or political independence of any state.’ While the Article makes clear that Russia’s invasion of Ukraine is illegal, it makes no mention of annexation. Those citing the Article focus on the methods used to obtain affirmative referendum votes, concluding that such methods employed force to challenge the territorial integrity of Ukraine. Reports of Russian soldiers bribing and threatening Ukrainians to vote affirmative are particularly concerning. However, because the Kremlin has denied this behaviour and the reports have not yet been proven, the UN Charter does not provide strong legal support for the West’s position. Nor does the Charter provide support for Putin’s ‘self-determination’ position. While the Charter acknowledges the right of self-determination, it does not provide details on what exactly that right entails, or how it may be expressed. The Charter alone, therefore, cannot either justify nor condemn Russia’s actions.

Other sources of international law do however undermine Russia’s claim that the annexation is legally permissible. Article 43 of the Hague Convention (of which Russia and Ukraine are signatories) provides that while an occupying state can assume control over public order in occupied territory, it must respect the laws of that territory. This is relevant because Article 73 of the Ukrainian Constitution provides that ‘altering the territory of Ukraine is resolved exclusively by an All-Ukrainian referendum.’ Consequently, in ignoring this Article, Russia, as the occupying state, has violated international law. Further, and perhaps more damning for Russia, is the Budapest Memorandum, which specifically concerns Russo-Ukrainian relations. The Memorandum provides that ‘the Russian Federation... reaffirm[s] their commitment to Ukraine... to respect the independence and sovereignty and the existing borders of Ukraine.’ In annexing part of Ukraine, Russia has thus directly violated a treaty to which it is a primary signatory.

In addition to Ukrainian and Russian-specific documents, other sources of international law provide clarity regarding the legality of forcibly annexing territory. The Declaration of the Principles of International Law, for example, declares ‘the territory of a State shall not be the object of acquisition by another state resulting from threat or use of force. No territorial acquisition resulting from the threat or use of force shall be recognized as legal.’ Russia’s annexation of Ukraine is illegal simply because it resulted from the use of force. Furthermore, Russia’s alleged method of securing pro-annexation votes violates the Fourth Geneva Convention: ‘no physical or moral coercion shall be exercised against protected persons.’ ‘Protected persons’ generally refers to civilians currently under the control of an adverse power, meaning that if Russian troops did coerce voters, the referenda would still be considered invalid under international law.

Finally, legal scholars have also condemned Russia’s purported annexation. Professor Eliav Lieblich, an expert on the law of occupation, has stated that international law prioritises territorial sovereignty of the occupied state. Ukraine is the only body that can decide if the disputed regions may change hands. Even if the referenda were to be legally conducted, the entirety of the Ukrainian state–not just the disputed regions–must freely consent to the change in territory. The importance of territorial sovereignty would remain even if the international community agreed with Putin’s recognition of the Donbas’ independence. Both territories would still need to freely consent to the annexation.

Occupation experts have also specifically compared Russia’s actions to that of Iraq in 1990. Iraq’s invasion and subsequent ‘annexation’ of Kuwait was widely condemned as illegal by the international community because of the overwhelming force used and the lack of Kuwaiti consent. Unanimously adopted (including by the then Soviet Union), Security Council Resolution 662 states: the annexation had ‘no legal validity, and is considered null and void.’ Finding many parallels between the actions of Iraq and Russia, scholars consider Resolution 662 a precedent-setting document, reinforcing the conclusion that Russia’s annexation of Ukrainian territory is invalid under international law.

The international community has widely condemned Russia’s referenda in four Ukrainian regions and the subsequent ‘annexation’ of those regions as violative of international law. While some have incorrectly stated that these actions are contrary to the UN Charter, it is clear upon studying other sources of international law that Russia’s purported annexation explicitly violates international law.


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