I'll examine claims about Russia's invasion and how international law assesses them.
Russia's invasion of Ukraine, launched on February 24, 2022, is described by Russia as a "special military operation". Whether it is justified depends on the framework used to evaluate it — Russian security and political claims versus international law.
1. Russia's Stated Justifications
Russian authorities have given several overlapping reasons:
•Protection of Donbas: Objectives including the protection of the Donetsk and Luhansk People's Republics in the Donbas. President Vladimir Putin said the purpose was to "protect people who, for eight years now, have been facing humiliation and genocide perpetrated by the Kiev" regime and that "Russia could not but come to the rescue of the long-suffering people of Donbass".
•Denazification and Demilitarization: When Vladimir Putin ordered the invasion on 24 February 2022, he stated that the goal was to 'denazify' Ukraine and to protect the people of Donbas from an 'abusive' and 'genocidal' regime in Kyiv. In the UN Security Council Russia stated: "We are carrying out a special operation against nationalists to protect the residents of Donbas and for the purposes of denazification and demilitarization".
•Other claims: This later expanded to include need to protect Russian-speaking populations and allegations of "genocide" in Donbas or alleged biological weapons development programmes, with Russia claiming it was acting in self-defense.
•NATO expansion and security concerns: From Russia's perspective, NATO's support for Ukraine is seen as an existential threat. Moscow has frequently cited NATO's enlargement as a justification for its military actions, including the annexation of Crimea in 2014 and the 2022 invasion. Russia justifies its invasion by claiming that NATO broke its promise not to expand eastward. More generally, Russia cites historical ties, security concerns related to NATO expansion, and the strategic importance of energy and geography.
Academic debate notes this divide: Realists tend to think NATO's post-Cold War eastward expansion and dismissal of Russian security concerns increased odds of a violent reaction from Moscow, while liberals believe the character of the Russian regime caused the invasion without provocation. Even analysts who emphasize NATO expansion as background often conclude the invasion itself has no moral justification.
2. Ukraine's and the International Community's Position
Ukraine, and the large majority of states and international legal bodies, reject those justifications:
•Violation of UN Charter: Russia's illegal war of aggression blatantly breaches the core principles and rules of the UN Charter, including sovereignty and territorial integrity, and constitutes a manifest violation of international law, including the UN Charter and resolutions of the General Assembly.
•UN General Assembly condemnation: The UN Charter, the Secretary-General, and the Assembly itself had been clear – Russia's invasion, and attempted annexation of Ukrainian territory by force, "is illegal". On October 12, 2022, the UN General Assembly adopted Resolution ES-11/4 in which 143 states unequivocally condemned Russia-organized illegal pseudo-referendums and the attempted unlawful annexation.
•International Court of Justice (ICJ): Ukraine brought a case alleging Russia premised its invasion on fabricated claims of Ukrainian genocide against Russians or Russian-speakers. The ICJ said it "is not in possession of evidence substantiating the accusation... that genocide has been perpetrated on Ukrainian soil" and ultimately rejected Russian allegations and issued an interim measure ordering Russia to halt the invasion, finding "Russia had no right to armed intervention".
3. Legal Assessment
In international law scholarship, the conclusion is widely stated as:
> A lawful justification for Russia's military invasion ... does not exist; the various claims advanced by Russia not only all fail, but most of them fail on multiple grounds. The invasion constitutes an unlawful use of force, an act of aggression and an egregious violation of a rule of jus cogens.
NATO expansion is also assessed as not providing a legal justification: NATO's expansion did not violate any binding international agreement with Russia. Verbal assurances in 1990 were informal and context-specific to German reunification, not a legal commitment, while Russia's invasion directly violated explicit commitments such as the Budapest Memorandum.
Under UN General Assembly Resolution 3314, wars made outside of self-defense or without UN Security Council authorization represent "a crime against international peace".
Summary
•From Russia's official perspective: The operation is portrayed as forced and defensive — necessary to protect Russians in Donbas, prevent NATO encirclement, and neutralize perceived threats from Ukraine.
•From Ukraine's perspective and under prevailing international law: There is no recognized right to use force on these grounds. The invasion is viewed as unprovoked, illegal, and in violation of sovereignty and the prohibition on acquiring territory by force.
Most governments and international courts have therefore concluded the invasion is not legally justified, while acknowledging that Russian security concerns about NATO are part of the political context cited by Moscow.