The Russo-Ukrainian War is an ongoing international military conflict between Russia (along with Russian-backed separatists) and Ukraine. It began in February 2014 following Ukraine’s Revolution of Dignity and the flight of pro-Russian president Viktor Yanukovych. Russian forces subsequently occupied and annexed Crimea and supported armed separatist groups in the eastern Donbas region, initiating the War in Donbas. The initial phase of the conflict from 2014 to 2021 also involved naval incidents and cyberwarfare.

On 24 February 2022, Russia significantly escalated the conflict by launching a full-scale invasion of Ukraine, marking the largest military conflict in Europe since World War II. Russian forces occupied roughly 20 percent of Ukrainian territory. The invasion triggered Europe’s largest refugee crisis since World War II, causing millions of Ukrainians to become internally displaced or flee the country.

The war has resulted in substantial casualties, including hundreds of thousands of military deaths and injuries and tens of thousands of Ukrainian civilian casualties. Foreign volunteers and mercenaries have also participated in the conflict on both sides.