The war between Russia and Ukraine began in February 2014 with Russia's covert invasion and annexation of Crimea, and the support of Russian-backed separatists in the eastern Donbas region of Ukraine. This conflict is widely regarded as the start of the Russo-Ukrainian War. The war escalated significantly on February 24, 2022, when Russia launched a full-scale invasion of Ukraine, marking the beginning of the largest and deadliest phase of the conflict.

Early Conflict in 2014

• In February 2014, following Ukraine's Revolution of Dignity, Russia occupied Crimea and annexed it after a disputed referendum.
• Russian-backed militants seized towns in the Donbas region, starting active conflict with Ukraine's military.
• This phase included covert military operations, paramilitary involvement, and resulted in years of fighting primarily in eastern Ukraine.

Full-Scale War from 2022

• On February 24, 2022, Russia launched a large-scale military invasion across multiple fronts in Ukraine.
• It marked the biggest conflict in Europe since World War II, involving massive military assaults and widespread combat.

Thus, the war started as a covert and localized conflict in 2014 but expanded into a full-scale war in 2022. The entire war is often considered to have been ongoing since 2014, with a major escalation in 2022.