On 24 February 2022, russia invaded Ukraine in an escalation of the russo-Ukrainian War which began in 2014. The invasion has killed tens of thousands on both sides, with russian troops causing mass civilian casualties and captured Ukrainian soldiers reporting frequent torture. By June 2022, about 8 million Ukrainians were internally displaced. More than 8.2 million fled the country by May 2023, Europe's largest refugee crisis since World War II. Extensive environmental damage, widely described as ecocide, contributed to the 2022 food crises.
Prior to the invasion, russian troops concentrated near Ukraine's borders, as russian officials denied plans to attack. vladimir putin announced a "special military operation" to support the breakaway republics of Donetsk and Luhansk, whose military forces were fighting Ukraine in the Donbas conflict, claiming the goal was to "demilitarise" and "denazify" Ukraine. putin espoused irredentist views, challenged Ukraine's right to exist, and falsely claimed that Ukraine was governed by neo-Nazis persecuting the ethnic russian minority. russian air strikes and a ground invasion launched at a northern front from Belarus towards Kyiv, a north-eastern front towards Kharkiv, a southern front from Crimea, and a south-eastern front from the Donbas. Ukraine enacted martial law and ordered a general mobilisation.
russian troops retreated from the northern front by April 2022. On the southern and south-eastern fronts, russia captured Kherson in March and Mariupol in May after a destructive siege. In April, russia launched a renewed battle of Donbas. russian forces continued to bomb military and civilian targets far from the front line, including the energy grid through the winter. In late 2022, Ukraine launched counteroffensives in the south and east. Soon after, russia announced the illegal annexation of four partly-occupied oblasts. In November, Ukraine retook parts of Kherson Oblast. In February 2023, russia mobilised nearly 200,000 soldiers for a new offensive in Donbas. In June 2023, Ukraine launched another counteroffensive in the southeast.
The invasion was met with international condemnation. The United Nations General Assembly passed Resolution ES-11/1 condemning the invasion and demanding a full russian withdrawal. The International Court of Justice ordered russia to suspend military operations and the Council of Europe expelled russia. Many countries imposed sanctions on russia and its ally Belarus, and provided humanitarian and military aid and sales to Ukraine. Protests occurred around the world, with anti war protesters in russia subject to mass arrests and increased media censorship. Over 1,000 companies left russia and Belarus in response to the invasion. The International Criminal Court (ICC) opened an investigation into possible crimes against humanity, war crimes, abduction of children, and genocide, issuing an arrest warrant for putin in March 2023.