section_path: Abstract
section_name: Abstract
paragraph_text: On 24 February 2022, Russia invaded Ukraine, starting the largest and deadliest war in Europe since World War II, in a major escalation of the conflict between the two countries which began in 2014. The fighting has caused hundreds of thousands of military casualties and tens of thousands of Ukrainian civilian casualties. As of 2025, Russian troops occupy about 20% of Ukraine. From a population of 41 million, about 8 million Ukrainians had been internally displaced and more than 8.2 million had fled the country by April 2023, 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 the NATO military alliance. After repeatedly denying having plans to attack Ukraine, on 24 February 2022, Russian president Vladimir Putin announced a " special military operation ", saying that it was to support the Russian-backed breakaway republics of Donetsk and Luhansk, whose paramilitary forces had been fighting Ukraine in the war in Donbas since 2014. Putin espoused irredentist and imperialist views challenging Ukraine's legitimacy as a state, baselessly claimed that the Ukrainian government were neo-Nazis committing genocide against the Russian minority in the Donbas, and said 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 Crimea, and an eastern front from the Donbas and 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. In the southeast, 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 the 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 Kherson. In June 2023, Ukraine launched another counteroffensive in the southeast but made few gains. 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 assist Russia. The United Nations Human Rights Office reports that Russia is committing severe human rights violations in occupied Ukraine. The direct cost of the war for Russia has been over US$450 billion.
  
  The invasion was met with widespread international condemnation. The United Nations General Assembly passed a resolution condemning the invasion and demanding a full Russian withdrawal. The International Court of Justice ordered Russia to halt military operations, and the Council of Europe expelled Russia. Many countries imposed sanctions on Russia and its ally Belarus and provided large-scale humanitarian and military aid to Ukraine. The Baltic states and Poland declared Russia a terrorist state. Protests occurred around the world, with anti-war protesters in Russia being met by mass arrests and greater media censorship. The Russian attacks on civilians have led to allegations of genocide. War-related disruption to Ukrainian agriculture and shipping contributed to a world food crisis; war-related local environmental damage has been described as ecocide and the war has heavily disrupted global climate policy. 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.