On 24 February 2022, , starting the largest and deadliest war in Europe since World War II, in a major escalation of the existing war between the two countries that began when Russia attacked Ukraine in 2014. The fighting has caused hundreds of thousands of military casualties and tens of thousands of Ukrainian civilian casualties. From a population of 41 million, about 8 million Ukrainians have been internally displaced and 6–7 million have fled the country, creating Europe's largest refugee crisis since World War II.
In late 2021, Russia massed troops near Ukraine's borders and issued demands to the West, including a ban on Ukraine ever joining NATO. After repeatedly denying having plans to attack Ukraine, on 24 February 2022, Russian president Vladimir Putin announced a "special military operation," saying it was to support the Russian-backed breakaway republics of Donetsk and Luhansk, whose paramilitary forces had been fighting Ukraine in the Donbas war since 2014. Putin espoused irredentist and imperialist views challenging Ukraine's legitimacy as a state. He claimed without evidence that the Ukrainian government were neo-Nazis committing genocide against the Russian minority in the Donbas and that Russia's goal was to "demilitarise and denazify" Ukraine. Russian air strikes and a ground invasion were launched on a northern front from Belarus towards the capital, Kyiv; a southern front from occupied Crimea; and an eastern front from the Donbas towards Kharkiv. Ukraine enacted martial law, ordered a general mobilisation, and severed diplomatic relations with Russia.
Russian troops retreated from the north and the outskirts of Kyiv by April 2022, after encountering stiff resistance and logistical challenges. The Bucha massacre was uncovered after their withdrawal. Russia launched an offensive in the Donbas and captured Mariupol after a destructive siege. Russia continued to bomb military and civilian targets far from the front and struck Ukraine's energy grid during winter months. In late 2022, Ukraine launched successful counteroffensives in the south and east, liberating most of Kharkiv Oblast. Soon after, Russia illegally annexed four partly occupied provinces. In November, Ukraine liberated the city of Kherson and all land west of the Dnipro River. After small but steady Russian advances in the east in the first half of 2024, Ukraine launched a cross-border offensive into Russia's Kursk Oblast in August, where North Korean soldiers were sent to help Russia.
The United Nations Human Rights Office reports that Russia is committing severe human rights violations in occupied Ukraine. Russia's attacks on civilians, as well as its policies in occupied territories, have led to allegations of genocide. The direct cost of the war for Russia has been estimated as over US$450 billion, while the World Bank Group estimates the cost of reconstruction in Ukraine at US$588 billion.
The Russian invasion was met with international condemnation. Many countries imposed sanctions on Russia and its ally Belarus while providing humanitarian and military aid to Ukraine. Protests occurred around the world. Within its borders, Russia met anti-war protesters with mass arrests and greater media censorship. War-related disruption to Ukrainian agriculture and shipping worsened the world food crisis; war-related environmental damage was described as ecocide. The International Criminal Court (ICC) opened an investigation into crimes against humanity, war crimes, abduction of Ukrainian children, and genocide against Ukrainians. The ICC issued arrest warrants for Putin and five other Russian officials. Peace negotiations have stalled, and Russia has repeatedly refused calls for a ceasefire.
Background
Post-Soviet relations
After the dissolution of the Soviet Union in 1991, Russia and Ukraine maintained cordial relations. In return for security guarantees, Ukraine signed the Nuclear Non-Proliferation Treaty in 1994 and gave up its nuclear weapons. Russia, the US, and the UK agreed in the Budapest Memorandum to respect Ukraine's sovereignty and borders. In 1999, Russia signed the Charter for European Security, affirming that every country had the right "to choose or change its security arrangements" and to join military alliances. In 2005, Putin said that if Ukraine wanted to join NATO, "we will respect their choice".
Ukrainian revolution
In 2013, Ukraine's parliament approved finalising the European Union–Ukraine Association Agreement. The Putin regime put pressure on Ukraine to reject the agreement and imposed economic sanctions on the country. Kremlin adviser Sergei Glazyev warned in September 2013 that if Ukraine signed the EU agreement, Russia would no longer acknowledge Ukraine's borders.
In November, Ukrainian president Yanukovych suddenly withdrew from signing the agreement, choosing closer ties to Russia instead. This coerced withdrawal sparked massive protests known as Euromaidan, culminating in the Revolution of Dignity in February 2014. Almost 100 protesters were killed by state forces, most of them shot by police snipers. Despite signing an agreement, Yanukovych secretly fled to Russia. Ukraine's parliament then voted to remove him and hold new elections, which elected Petro Poroshenko as President of Ukraine.
Russian invasion of Crimea and Donbas
On 27 February 2014, Russian soldiers with no insignia began to occupy the Ukrainian territory of Crimea, blockading Ukrainian military bases. In March, Russia annexed Crimea following an illegitimate referendum held under occupation. It was the first time since World War II that a European country had annexed part of another, and several scholars likened it to Nazi Germany's annexation of Austria. The UN General Assembly adopted a resolution affirming the "territorial integrity of Ukraine" and rejecting the annexation. NATO also suspended cooperation with Russia. Putin said Crimea should never have been part of an independent Ukraine and claimed that Russia did not want to take any other regions of Ukraine.
Pro-Russian protests followed in the Ukrainian cities of Donetsk and Luhansk, covertly funded and organised by Russia. In April 2014, armed Russian paramilitaries seized Sloviansk and other settlements, proclaiming the independent Donetsk People's Republic (DPR) and Luhansk People's Republic (LPR). Their commander, Igor Girkin, acknowledged that this sparked the War in Donbas, as Ukraine soon launched an operation to retake the territory. Russia covertly supported the separatists with troops, tanks and artillery. The International Criminal Court judged that the war was a national and international armed conflict involving Russia, and the European Court of Human Rights judged that Russia controlled the DPR and LPR from 2014 onward. Ukraine's parliament declared the Donbas region to be occupied by Russia.
The annexation of Crimea and the Donbas war sparked a wave of Russian nationalism. Analyst Vladimir Socor called Putin's 2014 speech following the annexation a "manifesto of Greater Russia irredentism." Putin began referring to "Novorossiya" (New Russia), a former Russian imperial territory that covered much of southern Ukraine. Russian-backed forces were influenced by Russian neo-imperialism and sought to create a new Novorossiya.
When the conflict began in 2014, Ukraine was officially neutral and said it was not seeking NATO membership. Following Russia's occupation of Crimea and invasion of the Donbas, Ukraine's parliament voted in December 2014 to revoke the country's neutral status and seek NATO membership.
The Minsk agreements (September 2014 and February 2015) aimed to resolve the Donbas War, but ceasefires and further negotiations failed. The West's weak response to Russian actions led Putin to believe the West would not react strongly to the 2022 invasion. Several political scientists said this encouraged further Russian aggression.
Prelude
Russian military buildup and demands
There was a Russian military build-up near Ukraine's borders in March and April 2021, and again in both Russia and Belarus from October 2021 onward. Russia said it was only holding military exercises. Members of its government, including Putin, repeatedly denied having plans to invade Ukraine, issuing denials up until the day before the invasion.
Russia's proxy forces launched thousands of attacks on Ukrainian troops in the Donbas. Observers from the Organization for Security and Co-operation in Europe (OSCE) reported more than 90,000 ceasefire violations throughout 2021, most in Russian-controlled territory.
In July 2021, Putin published "On the Historical Unity of Russians and Ukrainians," in which he called Ukraine "historically Russian lands" and claimed there is "no historical basis" for the "idea of Ukrainian people as a nation separate from the Russians." Putin was accused of promoting Russian imperialism, historical revisionism, and disinformation.
The December 2021 Russian ultimatum to NATO included demands that NATO end all activity in its Eastern European member states and ban Ukraine or any former Soviet state from ever joining the alliance. Russia's government said NATO was a threat and warned of a military response if it followed an "aggressive line." A US official said the US was willing to discuss the proposals, but there were some that "the Russians know are unacceptable" and had already been ruled out. NATO Secretary General Jens Stoltenberg replied that "Russia has no veto" on whether Ukraine joins and "has no right to establish a sphere of influence to try to control their neighbours." NATO underlined that it is a defensive alliance and had co-operated with Russia until the Crimea annexation.
Several Western political analysts suggested that Russia knew its "unrealistic demands" would be rejected, giving it a pretext to invade. No countries bordering Russia had joined NATO since 2004. Ukraine had not yet applied, and some NATO states would likely veto its membership. Analysts Taras Kuzio and Vladimir Socor agree that "when Russia made its decision to invade Ukraine, that country was more remote than ever not only from NATO membership but also from any track that might lead to membership." Political scientists Michael McFaul and Robert Person said Russia's occupation of Crimea and the Donbas had already blocked Ukraine's NATO membership; they suggested Putin's real aim was to subjugate Ukraine.
NATO offered to negotiate some of Russia's demands and to improve military transparency, as long as Russia stopped its troop buildup. The alliance rejected Russia's demand to keep Ukraine out of NATO forever, pointing out that Russia had signed agreements affirming the right of Ukraine and other countries to join alliances. The US proposed that it and Russia sign an agreement not to station missiles or troops in Ukraine. Putin replied that Russia's demands had been "ignored," and the Russian troop buildup continued.
Western leaders vowed heavy sanctions should Putin invade rather than negotiate. French president Emmanuel Macron and German chancellor Olaf Scholz met Putin in February 2022 to dissuade him from invading. Putin told Scholz that Ukraine should not be an independent state. Zelenskyy said Putin had broken agreements and could not be trusted to respect Ukrainian neutrality. At the Munich Security Conference, Zelenskyy called for Western powers to end their "appeasement" of Putin and give a timeframe for when Ukraine could join NATO.