- the prohibition against the threat and use of force in Article 2(4)
- individual and collective self-defence in case of an armed attack, in article 51;
- the collective security system falling within the Security Council’s competence in Chapter VII.
More generally, the prohibition against the threat and use of force in international relations constitutes a key principle of contemporary international law.
The actions taken by the Russian Federation since 24 February constitute a violation of Article 2(4) of the Charter, which states “[…] Members shall refrain in their international relations from the threat or use of force, whether against the territorial integrity or political independence of any State or in any other manner inconsistent with the Purposes of the United Nations”. The main questions arising to legally qualify Russian actions concern to both the sphere of jus ad bellum and jus in bello.
- What legal arguments have been invoked to justify the use of force by the Russian Federal Republic?
- How is the current situation framed from the point of view of international humanitarian law?
In relation to the first question, several justifications are invoked by the Russian authorities.
A) The so-called preventive self-defence
A complete exception to the absolute prohibition of the use of force is the right to self-defence, governed by Article 51 of the UN Charter, in the event of an armed attack. This article provides that nothing in the Charter (thus including the prohibition in Article 2(4)) shall affect the natural right of individual or collective self-defence in the event of an ‘armed attack against a Member of the United Nations. The Russian authorities have referred to the right of self-defence. However, they have referred to a particular aspect of this prerogative, namely the so-called right of preventive self-defence.
However, the latter does not constitute an internationally accepted argument since it does not have any of the preconditions of the right to self-defence:
- the immediacy of the threat (self-defence is in response to an armed attack in progress)
- the necessity of the response (the action must be taken absolutely as a last resort in order to resist and reject the armed attack)
- proportionality: the action must be proportionate not only to the attack suffered but above all to the end it pursues (defence proportionate to the offence), which is to restore the situation before the attack.
Moreover, the exercise of this right must be in response to an armed attack. Therefore, it cannot be a preventive measure aimed at avoiding a future armed attack by others, even if it is perceived as imminent.
Russia itself condemned the principle of pre-emptive self-defence during the US intervention in Iraq in 2003.
B) Collective Legitimate Defence
If the alleged ontological reason for the exercise of a right to pre-emptive self-defence is not acceptable, the argument of collective legitimate defence does not fit the present case either: the Russian Federation has declared that it acted in collective defence at the request of the Donetsk and Luhansk People’s Republics, two non-state entities recognised as unilaterally independent by Russia itself. However, these territories still remain Ukrainian regions and not states under international law.
In short, the argument of legitimate defence, preventive or collective, is not acceptable.
C) Peacekeeping intervention and the self-determination of peoples
Another argument the Russian Federal Republic invoked to derogate from the absolute prohibition of Article 2(4) is that of humanitarian intervention. Indeed, the Russian Federation has also qualified the current action as a peacekeeping operation, accusing the Ukrainian government of persecution and genocide perpetrated against the Russian minorities in the Donbas.
Yet, to act under the instrument of humanitarian intervention, there must be a gross and systemic violation of human rights by a state that is unwilling or unable to protect its people. The Ukrainian government’s treatment of the Russian minority in the Donbas region does not seem objectively qualifiable in terms of persecution or genocide, as suggested by Russia. The narrative of defending the Russian minorities does not, moreover, justify a legitimate casus belli, not even in the name of the principle of self-determination of peoples. In international law, reference to this principle is admitted only in three circumstances, namely when it is established that peoples are subject to colonial domination, foreign occupation or racist regimes (see Article 1(4) of the 1977 First Additional Protocol to the Geneva Conventions and Article 1 of the 1996 Covenant on Civil and Political Rights). Therefore, apart from the three specific exceptions above, the principle of states’ sovereignty and territorial integrity is inviolable, and no ‘right to secession’ deriving from the self-determination of peoples can be claimed.
D) The so-called remedial secession
The other aspect of self-determination is internal and concerns the right of minorities to choose their political status freely and to pursue economic, social and cultural development within the state – as the Minsk Agreements aimed to secure for the Donets’k and Luhans’k territories.
A specific part of the doctrine recognises a right to remedial secession in positive international law only in intolerable discrimination and systematic oppression. Secession would be an extreme recourse for the minority when it is systematically denied participation in the majority state’s political, economic, and social choices (see Reference re Secession of Quebec 1998 2 S.C.R. 217). Neither the OSCE Special Observer Mission to Ukraine nor the UN Human Rights Monitoring Mission to Ukraine support such assumptions in their assessment reports.
It should also be highlighted that although Ukraine’s language law has been criticised, this cannot legitimise Russia’s accusations and the application of the so-called remedial secession.
This theory has been supported in the past by some countries at the International Court of Justice (ICJ) about Kosovo’s declaration of independence from Serbia. However, it should be noted that the Russian Federation itself stated on that occasion that the right to remedial secession is limited to extreme circumstances, such as an actual armed attack by the majority state, which threatens the survival of the concerned people (see Russia’s submissions to the ICJ in the Kosovo Case, para. 88).
All in all, the conduct of the Russian Federal Republic in Ukraine constitutes an act of aggression that violates the noyau dur of Article 2(4) of the Charter of the United Nations, a clear rule of law.
In particular, the part of jus cogens provided for in that article refers to the massive use of force: the Russian actions fall within the definition of armed attack/aggression in international relations under Article 3 UN General Assembly Resolution 3314 (XXIX). This aggression can be defined as such, even regardless of a declaration of war.
Turning to the second question, from the jus in bello point of view, the situation outlined between the Russian Federation and Ukraine can be qualified as an international armed conflict. A global armed conflict must also be discussed about the military operations between Ukraine and the entities of Donets’k and Luhans’k since the conflict cannot be qualified here in part as a civil war, since the separatist republics are under effective Russian control. It is also important to emphasise – in this context – how Belarus can be considered a co-aggressor: according to Article 3 former Resolution 3314 (XXIX) of the United Nations General Assembly, aggression is considered to be the action of a State which provide its territory, which it has made available to another State, to be used by that other State to perpetrate an act of aggression against a third State.
There are several instruments that the international community has to respond to such violations.
A) The right to self-defence
The first possible option would be to invoke the above-mentioned right to self-defence under Article 51 of the UN Charter. Clearly already exercised by Ukraine under attack, this right could, theoretically, translate into collective self-defence if applied by third states. These could, in fact, with Ukrainian consent, decide to exercise this right, without the need to request prior authorisation from the United Nations Security Council (UNSC).
The Article 51 mechanism, however, requires that the action of individual and collective self-defence be immediately communicated to the CoS, and then cease when the latter adopts the measures necessary for the maintenance and restoration of international peace and security. However, no country has intended, or intends, to take such action at the moment.
B) The United Nations collective security system
The second possible way is to resort to the collective security system of the United Nations, which provides for actions of the Security Council that can be activated in the event of threats to peace, breach of peace or acts of aggression (Chapter VII of the Charter).
The CoS, in order to prevent a worsening of the situation, could in fact respond with a spectrum of provisional measures under Article 40 of the Charter (such as a call for a ceasefire, a call for the withdrawal of troops, a last warning), and then move on to recommendations or measures not involving the use of armed force (total or partial interruption of economic relations and rail, sea, air, postal, telegraphic, radio and other communications, and the severing of diplomatic relations under Article 41 of the Charter) or, at the very least, measures involving the use of armed force (peace enforcement operations under Article 42 of the Charter). The veto right exercised by the Russian Federation as a permanent member of the CoS makes it impossible to use this body.
It is significant in this respect that the attack on Ukraine started just as a CoS meeting was taking place at Ukrainian request. Russia has already voted against a CoS resolution that would have ‘absolutely deplored’ the invasion of Ukraine. China has also decided to abstain.
C) The UN General Assembly initiative
In the absence of a legitimate defence response from third states or in the absence of a CoS initiative, other avenues are open. One could resort to initiatives at the level of the UN General Assembly. For example, the use of resolution 377 A (V), ‘Uniting for peace’, adopted by the General Assembly on 3 November 1950, in the event of a Security Council impasse would confer Chapter VII and VIII powers on the Assembly. This practice does not yet seem to have established itself as usual at the international level, lacking both the element of diuturnitas (there has been, so far, a limited practice) and that of opinio iuris ac necessitatis (which is manifest in the persistent opposition of part of the international community). Nevertheless, the United States announced its willingness to transfer the resolution condemning military aggression against Ukraine to the United Nations General Assembly, where the Russian Federation does not have a veto right. On 28 February, the General Assembly met in a rare emergency session (the eleventh in history) convened by the Security Council.
According to the resolution “Uniting for peace”, an “emergency special session” can be convened by the CoS within 24 hours “[…] if the Security Council, in the absence of unanimity of the permanent members, should fail to fulfil its primary task of maintaining international peace and security, if any threat to the peace, breach of the peace or act of aggression should arise”. Under such circumstances, “the General Assembly shall immediately take up the matter and make appropriate recommendations to Members for collective measures to be taken, including, if necessary, in the event of a breach of the peace or acts of aggression, the use of armed forces, to maintain or restore international peace and security”.
The session was held between 28 February and 2 March. Yesterday there was a vote on a resolution in which the international community
– strongly condemns Russian aggression as a violation of Article 2(4) of the Charter;
– demands that the Russian Federation immediately cease the use of force against Ukraine and refrain from any further threats or unlawful use of force against any state;
– Demands that the Russian Federation immediately, completely and unconditionally withdraw all its military forces from the territory of Ukraine within its internationally recognised borders;
– deplores the decision of 21 February 2022 of the Russian Federation on the status of certain areas of the Donetsk and Luhansk regions of Ukraine as a violation of the territorial integrity and sovereignty of Ukraine not in accordance with the principles of the Charter.
The resolution, supported by 141 of the Assembly’s 193 members, was voted against only by Russia, Belarus, Eritrea, North Korea and Syria. Thirty-five members, including China and India, abstained. The text of the resolution also reaffirms the obligation of member states not to recognise any illegitimate territorial acquisition resulting from the threat or use of force, with particular reference to the sovereignty and territorial integrity of Ukraine. Although General Assembly resolutions are non-binding, they carry considerable political weight, and Wednesday’s vote will help increase Russia’s international isolation.
We would like to thank Dr Ilaria Briglia of the School of International Studies in Trento and the Scuola Superiore Sant’Anna in Pisa for her support in collecting helpful material for this article. The opinions expressed by the author do not in any way commit its organisation and are the result of individual study and research.
 Charter of the United Nations (1945).
 Bascone, F. (24 febbraio 2022). La guerra “preventiva” di Vladimir Putin. Istituto Affari Internazionali.
 Dinstein, Y. (2017), War, aggression and self-defence. Cambridge University Press.
 “If we allow international law to be replaced by “the law of the fist” whereby the strong is always right and has the right to do anything and in choosing methods to achieve his goals is not constrained by anything, then one of the basic principles of international law will be put into question, and that is the principle of immutable sovereignty of a state”. Relief Web (2003), Statement by President Putin on Iraq at a Kremlin meeting.
 BBC NEWS (21 febbraio 2022). Ukraine: Putin announces Donetsk and Luhansk recognition.
 BBC NEWS (10 dicembre 2021). Russia Ukraine: Putin compares Donbas war zone to genocide.
 United Nations Office on Genocide Prevention and the Responsibility to Protect. Responsibility to Protect.
 Protocol I on the Protection of Victims of International Armed Conflicts, supplementing the Conventions of 12 August 1949 (1977).
 International Covenant on Civil and Political Rights (1966).
 The negotiations that led to those agreements, signed in 2014 with the aim of resolving the ongoing secessionist conflict in the eastern Ukrainian regions, had included the issue of autonomy in the economic and social life of the Russian minorities in the Donets’k and Luhans’k territories. Protocol on the results of consultations of the Trilateral Contact Group with respect to the joint steps aimed at the implementation of the Peace Plan of the President of Ukraine, P. Poroshenko,and the initiatives of the President of Russia, V. Putin (Minsk Protocol, or Minsk I Agreement).
 OSCE SPECIAL MONITORING MISSION TO UKRAINE. Daily and spot reports from the Special Monitoring Mission to Ukraine.
 Ukraine – OHCHR Reports. Reports on the human rights situation in Ukraine.
 It is worth reading the Written Statement submitted to the International Court of Justice by the Swiss Confederation: Accordance with International Law of the Unilateral Declaration of Independence by the Provisional Institutions of Self-Government of Kosovo, 2009.
 WRITTEN STATEMENT BY THE RUSSIAN FEDERATION. Advisory Opinion Accordance with International Law of the Unilateral Declaration of Independence by the Provisional Institutions of Self-Govemment of Kosovo, 2009.
 United Nations General Assembly Resolution 3314 (XXIX), 14 December 1974 Pubblicazioni Centro italiano Studi per la pace.
 «[…] until the Security Council has taken measures necessary to maintain international peace and security. Measures taken by Members in the exercise of this right of self-defence shall be immediately reported to the Security Council and shall not in any way affect the authority and responsibility of the Security Council under the present Charter to take at any time such action as it deems necessary in order to maintain or restore international peace and security». Art. 51 Charter of the United Nations (1945).
 “Should the Security Council consider that measures provided for in Article 41 would be inadequate or have proved to be inadequate, it may take such action by air, sea, or land forces as may be necessary to maintain or restore international peace and security. Such action may include demonstrations, blockade, and other operations by air, sea, or land forces of Members of the United Nations.” Article 42 Charter of the United Nations (1945).
 Fassihi, F. (24 febbraio 2022). The U.N. Security Council met to prevent military action by Putin. Russia invaded Ukraine as they spoke. The New York Times.
 Locatelli, N. (26 febbraio 2022). L’astensione di Pechino al Consiglio di Sicurezza sulla risoluzione contro l’invasione russa non è un’ottima notizia per Mosca. Limes Online.
 Adnkronos (26 febbraio 2022). Invasione in Ucraina, veto Russia su risoluzione Onu.
 Meetings Coverage, GENERAL ASSEMBLY PLENARY ELEVENTH EMERGENCY SPECIAL SESSION, 1ST & 2ND MEETINGS (AM & PM), GA/12404, 28 FEBRUARY 2022.
 A/RES/377 (V) Uniting for peace. Adopted at the Three Hundred and Second Plenary Meeting, 3 November 1950. Pubblicazioni Centro italiano Studi per la pace.
*Advisor Maeci – Member of the Scientific Committee of Eurispes.