Russo-Ukrainian War in the context of "Donetsk Oblast"

The Russian-occupied territories of Ukraine are areas of southern and eastern Ukraine that are controlled by Russia as a result of the Russo-Ukrainian War and the ongoing invasion. In Ukrainian law, they are defined as the "temporarily occupied territories". As of 2024, Russia occupies almost 20% of Ukraine and about 3 to 3.5 million Ukrainians are estimated to be living under occupation; since the invasion, the occupied territories lost roughly half of their population. The United Nations Human Rights Office reports that Russia is committing severe human rights violations in occupied Ukraine, including arbitrary detentions, enforced disappearances, torture, crackdown on peaceful protest and freedom of speech, enforced Russification, passportization, indoctrination of children, and suppression of Ukrainian language and culture.

The occupation began in 2014 with Russia's invasion and annexation of Crimea, and its de facto takeover of Ukraine's Donbas during a war in eastern Ukraine. In 2022, Russia launched a full-scale invasion. However, due to fierce Ukrainian resistance and logistical challenges (e.g. the stalled Russian Kyiv convoy), the Russian Armed Forces retreated from northern Ukraine in early April. In September 2022, Ukrainian forces launched the Kharkiv counteroffensive and liberated most of that oblast. Another southern counteroffensive resulted in the liberation of Kherson that November.

On 27 February 2014, unmarked Russian soldiers were deployed to the Crimean Peninsula in order to wrest control of it from Ukraine, starting the Russo-Ukrainian War. This military occupation, which the Ukrainian government considers to have begun on 20 February laid the foundation for the Russian annexation of Crimea on 18 March 2014. Under Russia, the Ukrainian Autonomous Republic of Crimea was replaced by the Republic of Crimea, though the legitimacy of the latter is scarcely recognized internationally.

The occupation began during Ukraine's Revolution of Dignity, which ousted pro-Russian president Viktor Yanukovych. Russian special forces without insignia took control of Crimea's government buildings, surrounded Ukrainian military bases, and blockaded the peninsula. A pro-Russian government was installed and a referendum on Crimea's status was held under occupation. According to the Russian-installed authorities, the result was in favour of joining Russia. It annexed Crimea on 18 March 2014, re-organizing it as a Russian republic and turning Sevastopol into a Russian federal city.

The Russia–Ukraine border is the de jure international boundary between Russia and Ukraine. Over land, the border spans five Russian oblasts and five Ukrainian oblasts. Due to the ongoing Russo-Ukrainian War, which began in early 2014, the de facto border between Russia and Ukraine is different from the legal border recognized by the United Nations. As of 2024, Russia is militarily occupying a significant portion of Ukraine, and Ukraine is militarily occupying a very small portion of Russia.

According to a 2016 statement by Viktor Nazarenko, the head of the State Border Guard Service of Ukraine, the Ukrainian government did not have control over 409.3 kilometres (254.3 mi) of the international border with Russia. This stretch of land was formerly controlled by pro-Russian separatists under the Donetsk People's Republic and the Luhansk People's Republic (see War in Donbas), both of which were annexed by Russia in September 2022, seven months after the beginning of the ongoing Russian invasion of Ukraine. Ukraine has also not had authority over the Kerch Strait since 2014, when Russia annexed Crimea; the Ukrainian administration was pushed out of Crimea and Russian checkpoints were set up at the boundary with Kherson Oblast.

In February and March 2014, Russia invaded the Crimean Peninsula, part of Ukraine, and then annexed it. This took place in the relative power vacuum immediately following the Revolution of Dignity. It marked the beginning of the Russo-Ukrainian War.

The events in Kyiv that ousted Ukrainian president Viktor Yanukovych on 22 February 2014 sparked both pro-Russian and anti-separatism demonstrations in Crimea. At the same time, Russian president Vladimir Putin told his security chiefs to begin work on "returning Crimea to Russia". On 27 February, Russian special forces without insignia seized strategic sites across Crimea. Russia at first denied involvement, but Putin later admitted that they were Russian troops. As the armed men occupied Crimea's parliament, it dismissed the Crimean government, installed the pro-Russian Aksyonov government, and announced a referendum on Crimea's status. The referendum was held under Russian occupation and, according to the Russian-installed authorities, the result was overwhelmingly in favor of joining Russia. The next day, 17 March 2014, Crimea's authorities declared independence and requested to join Russia. Russia formally incorporated Crimea on 18 March 2014 as the Republic of Crimea and federal city of Sevastopol. Following the annexation, Russia militarized the peninsula and warned against any outside intervention.

The Armed Forces of Ukraine (AFU) are the military forces of Ukraine. All military and security forces, including the Armed Forces, are under the command of the president of Ukraine and subject to oversight by a permanent Verkhovna Rada parliamentary commission. They trace their lineage to 1917, while the modern armed forces were formed again in 1991. The Armed Forces of Ukraine are the fifth largest armed force in the world in terms of both active personnel as well as total number of personnel with the eighth largest (14th largest) defence budget in the world, and it also operates one of the largest and most diverse drone fleets in the world. Due to the ongoing Russo-Ukrainian War, the Ukrainian Armed Forces has been described as "the most battle-hardened in Europe," but has suffered many casualties.

Ukraine's armed forces are composed of the Ground Forces, the Air Force, the Navy, the Air Assault Forces, the Marine Corps, the Special Operations Forces, the Unmanned Systems Forces, and the Territorial Defense Forces. Ukraine's navy includes its own Naval Aviation. The Sea Guard is the coast guard service of Ukraine, and it is organized as part of the Border Guard Service, not subordinate to the navy. The National Guard serves as a paramilitary reserve component of the Armed Forces.

The Donbas (UK: /dɒnˈbɑːs/, US: /ˈdɒnbɑːs, dʌnˈbæs/; Ukrainian: Донбас [donˈbɑs]) or Donbass (Russian: Донбасс [dɐnˈbas]) is a historical, cultural, and economic region on the Russia-Ukraine border, lying predominantly in Ukraine. The vast majority of the Donbas is occupied by Russia as a result of the Russo-Ukrainian War, as the Russian Armed Forces control about 89% of the region as of October 2025.

The word Donbas is a portmanteau formed from "Donets Basin", an abbreviation of "Donets Coal Basin" (Ukrainian: Донецький вугільний басейн, romanized: Donetskyi vuhilnyi basein; Russian: Донецкий угольный бассейн, romanized: Donetskiy ugolnyy basseyn). The name of the coal basin is a reference to the Donets Ridge; the latter is associated with the Donets river.

The "little green men" (Russian: зелёные человечки, romanized: zelyonye chelovechki; Ukrainian: зелені чоловічки, romanized: zeleni cholovichky) were Russian soldiers who were masked and wore unmarked uniforms upon the outbreak of the Russo-Ukrainian War in 2014. They were active just before and during the Russian annexation of Crimea and carried regular weapons and equipment, but were always masked and wore distinctly unmarked green military fatigues. Russia, which had been denying any involvement in Ukraine prior to the annexation, used these little green men to give it plausible deniability on the international stage.

Between February and March 2014, these unmarked Russian soldiers occupied and blockaded the Simferopol International Airport, most of Ukraine's Crimean military bases, and the Supreme Council of Crimea. The name has also sometimes been used to refer to Russian troops during the War in Donbas; the Kremlin stated that no Russian troops were active in the region, but many little green men were operating in this region while disguised as pro-Russian separatists.

The Revolution of Dignity (Ukrainian: Революція гідності, romanized: Revoliutsiia hidnosti), also known as the Maidan Revolution or the Ukrainian Revolution, took place in Ukraine in February 2014 at the end of the Euromaidan protests. Scores of protesters were killed by government forces during clashes in the capital Kyiv. Parliament then voted to remove President Viktor Yanukovych, return to the 2004 Constitution of Ukraine, and call new elections. The revolution prompted Russia to occupy Crimea, starting the Russo-Ukrainian War.

In November 2013, a wave of large-scale protests known as "Euromaidan" began in response to President Yanukovych's sudden decision not to sign a political association and free trade agreement with the European Union (EU), instead choosing closer ties to Russia. Euromaidan soon developed into the largest democratic mass movement in Europe since 1989. The Verkhovna Rada (Ukrainian parliament) had overwhelmingly approved finalizing the EU association agreement; Russia had pressured Ukraine to reject it. The scope of the protests widened, with calls for the resignation of Yanukovych and the Azarov government. Protesters opposed what they saw as widespread government corruption and abuse of power, the influence of Russia and oligarchs, police brutality, human rights violations, and repressive anti-protest laws.