On February 24, 2022, the world awoke to a shocking announcement: Russia started its military invasion of Ukraine. World leaders quickly gathered to unite and organize emergency meetings to discuss the next strategic steps. The international community agrees that Putin’s actions are categorically deemed to violate international law (see, for instance, the statement of the UN Secretary General’s report). However, Putin references international law when the defense of his actions.

Two legal bases are mentioned through Putin during Putin’s speech to justify the attack.

The first is that Putin claims the Russian military intervention aligns with Art. 51 in the UN Charter that allows for self-defense for both individuals and groups in the event of an attack by force:

“In this regard, in accordance with Article 51 of Part 7 of the UN Charter, with the sanction of the Federation Council of Russia and in pursuance of the treaties of friendship and mutual assistance ratified by the Federal Assembly on February 22 this year with the Donetsk People’s Republic and the Luhansk People’s Republic, I decided to conduct a special military operation.”

And furthermore

“I repeat, our actions are self-defence against the threats posed to us and from an even greater disaster than what is happening today.”

In that context, there are two reasons to justify his position. On the side, the author argues that Russia acts in self-defense against a threat to its security. In a variant of this subject, Putin also refers to the republics of Donetsk and Luhansk that have demanded the Russian Federation for military assistance. It appears, therefore, that Putin wants to base his self-defense argument on two foundations: firstly, that Russia must defend itself, and secondly, that it is protecting two states.

Concerning Russian self-defense in its name, however, we acknowledge that there’s plenty of debate about specific conditions that govern self-defense rights (see Chris O’Meara, Necessity, and Proportionality as well as the right of Self-Defence in International Law(OUP 2021); see also here) According to well-established jurisprudence, there are two requirements that must be met: that is of necessity as well as reasonableness (see an ICJ’s Nicaragua case in paragraphs. 176, 194). Although they are the foundation of the international right to self-defense, the concepts of proportionality and necessity are not clearly defined in abstract legal terms, giving way to doubt. The ICJ did, however, declare that an attack armed is the essential condition for invoking the right of self-defense ( Nicaragua, para. 237). This condition cannot be fulfilled in the current scenario. Instead, the OSCE report’s findings seem to indicate the contrary in that violations of the ceasefire agreements relating to Donetsk and Luhansk were committed by Russian separatists. But even assuming there was an armed assault, the standard for determining whether self-defense is legally required is exceptionally high, as the ICJ stated in the Oil Platforms(para. 72): “(…) the obligation of international law that actions used in self-defence are to be required for a reason is a strict and objective that leaves no place to an “measure of discretion.” In addition, it was stated the ICJ also said that in Nicaragua is enacted that “the State that suffers the consequences of an attack by armed force (…) must organize and state that it was (…) targeted. No international law allows States to exercise its right to self-defence collectively by relying on their analysis of the circumstances. If collective self-defence has been invoked, it should be expected that the State to benefit from this right is being used has admitted that it is the target of an attack by armed strike.” (para. 195). Russia did not make the declaration for itself. However, Putin merely refers to NATO’s supposed expansionism, which he labels as

“ultimately it is a matter of death and life, an issue of our history and our future as a species. This isn’t an exaggeration. It is factual. This poses a real risk not only to our own interests as well as the very existence of our country and the sovereignty of which it is.”

In addition, the requirement of proportionality was not met due to the magnitude of Russia’s military intervention in Ukraine that extends beyond the region of separatism in Donetsk and Luhansk, which are uncertain at the very least (see the latest article). Russia was the only UN member that recognized the sovereign statehood of regions of separatism, and the most overwhelming reaction of the global community was a rejection of any notion.

Regarding the act of defense for both republics Donetsk and Luhansk, the same issues are raised, particularly concerning the requirement for an attack declaration made by the ‘State.’ Putin’s sole acknowledgment of the two republics cannot satisfy the statehood need.

The other legal basis that is impliedly cited is that of human rights violations or the concept of obligation to defend (R2P). Putin is implying this by justifying the need for the military incursion by citing the alleged genocide claimed to have occurred on Ukrainian soil for the past eight years:

“Its the military’s aim to safeguard those who have suffered violence and genocide from Kiev’s regime for Kiev regime for over eight years. We are determined to achieve the denazification and demilitarisation of Ukraine and the prosecution of the perpetrators of many, brutal acts against civilians, which included residents from Russia. Russian Federation.”

First, Russia’s claims of genocide in Ukraine do not have any evidence or data. The second reason is that humanitarian intervention and even the R2P doctrine R2P cannot circumvent the prohibition on recourse to force in Art—2 (4) of the UN Charter. The vast majority of international institutions and scholars, and the majority of UN members, do not agree with the idea (similarly in this article). The scope of Russia’s military operations in Ukraine is far beyond the needed or adequate level for any humanitarian purpose. Unknown numbers of civilian casualties and massive air strikes also impacting civilians could be something that needs to be considered in the future and may further weaken the need for humanitarian intervention.

If it is agreed there is no way to prove that any of the legal arguments offered by President Putin are valid, the next step is to consider what responsibilities the Russian President may be required to take on under international law. It is the case that the Russian Federation is accountable within the context of state accountability in the event of an infraction of Art. 2. (4) UN Charter and for the commission of acts of aggression. In addition, as defined in the Arts, Putin seems to have committed an act of aggression—5 and 8 bis of the Rome Statute of the International Criminal Court (ICC). Because neither Ukraine nor Russia is a state party to Rome Statute, the ICC does not have authority over the crime of aggression. The Court may investigate acts of genocide or crimes against humanity as well as war crimes that occur within the borders of Ukraine by the Ukrainian Declaration of 2015. Yet, examining the concept of aggression permits determining if the crime occurred.