| The Russia-Ukraine war history did not begin on February 24, 2022. Its roots run through the 1991 collapse of the Soviet Union, a 1994 nuclear disarmament deal that Russia eventually broke, eight years of low-intensity conflict in Donbas, and a chain of diplomatic failures that led to the largest land war in Europe since 1945. This article traces the full conflict from Soviet dissolution through the 2022 invasion and the war’s ongoing status in 2026, drawing on data from CSIS, CFR, OHCHR, and the ICC. |
The Russia-Ukraine war traces its origins to December 1991, when the Soviet Union dissolved, and Ukraine became an independent state for the first time in modern history. In the three decades that followed, a combination of a broken nuclear security deal, NATO’s eastward expansion, and Russia’s growing territorial ambitions built the conditions for Europe’s largest armed conflict since World War II. Universalnest tracks this conflict and 13 other active war zones as part of its global current affairs coverage, with history articles, weekly updates, and analysis for every conflict zone covered.
Ukraine in the Soviet Union: Why Independence Changed Everything
Ukraine was not a peripheral Soviet republic. It was the second-largest by population and the second-most powerful economically among the 15 Soviet republics, home to much of the USSR’s agricultural production, defence industries, and a large share of its military infrastructure.
When Ukraine declared independence in August 1991, Soviet leader Mikhail Gorbachev called it a deathblow to the union. On December 1, 1991, 92% of Ukrainians voted for independence in a national referendum, per CFR data. Seven days later, the leaders of Russia, Ukraine, and Belarus signed the Belavezha Accords on December 8, 1991, formally dissolving the Soviet Union.
Russia and Ukraine, once part of the same state, were now two separate sovereign nations with a shared border, a shared history, and a deepening disagreement about which direction each country should face.
The 1994 Budapest Memorandum: Nuclear Weapons and Broken Promises
In 1991, Ukraine inherited approximately 1,900 nuclear warheads from the Soviet Union, making it the world’s third-largest nuclear power overnight. Neither the United States nor Russia wanted a newly independent country of uncertain stability holding that arsenal.
Between 1991 and 1994, the US and Russia pressed Ukraine to surrender its nuclear weapons. Ukraine agreed, but demanded something in return: security guarantees from the powers that were asking it to disarm.
On December 5, 1994, Ukraine signed the Budapest Memorandum on Security Assurances with Russia, the United States, and the United Kingdom, per Arms Control Association records. Under the agreement:
- Ukraine transferred all nuclear warheads to Russia for dismantlement
- Russia, the US, and the UK pledged to respect Ukraine’s territorial integrity and existing borders
- All three pledged to refrain from the threat or use of force against Ukraine
The memorandum was not a legally binding treaty. It was a political commitment. By June 1996, Ukraine had transferred its last nuclear warhead to Russia.
Russia violated the Budapest Memorandum in 2014 by annexing Crimea, and again in 2022 by launching a full-scale invasion. The memorandum’s failure has since become a central argument in debates about nuclear non-proliferation: states considering disarmament point to Ukraine’s experience as evidence that security assurances without legal teeth offer no protection.
NATO’s Eastward Expansion and Russia’s Growing Alarm (1997-2008)
Russia opposed NATO’s eastward expansion from the moment the Cold War ended. In 1997, Russian President Boris Yeltsin formally requested a guarantee from US President Bill Clinton that NATO would never add former Soviet republics as members. Clinton refused.
Between 1997 and 2004, the following countries joined NATO:
| Year | Countries Joining NATO |
| 1999 | Poland, Hungary, Czech Republic |
| 2004 | Estonia, Latvia, Lithuania, Bulgaria, Romania, Slovakia, Slovenia |
Each expansion moved NATO’s eastern border closer to Russian territory by hundreds of kilometres.
The moment that changed Russian calculations most sharply came at NATO’s April 2008 Bucharest summit. Despite opposition from France and Germany, the alliance issued a declaration stating that Ukraine and Georgia “will become members of NATO.” Vladimir Putin attended the summit and issued an explicit warning: Ukrainian NATO membership was a red line. His warning was noted and then largely disregarded.
The Bucharest declaration gave Ukraine no timeline, no membership action plan, and no actual path to entry. But it gave Russia a stated justification it would reference repeatedly in the years that followed.
The 2013-2014 Maidan Revolution: The Turning Point
In November 2013, Ukrainian President Viktor Yanukovych abruptly suspended negotiations on an association agreement with the European Union, announcing he would strengthen ties with Russia instead. Mass protests erupted in Kyiv’s central Maidan square.
The protests grew through the winter. On February 18-20, 2014, government snipers opened fire on protesters in Kyiv, killing scores of people. Yanukovych fled to Russia on February 21. Ukraine’s parliament removed him from office and installed an interim government that announced it would sign the EU agreement.
Russia declared the change of government an illegal coup and refused to recognise the new administration. Within days, unidentified soldiers in unmarked uniforms began seizing strategic facilities on the Crimean peninsula. Ukrainian soldiers later identified them as Russian troops. Putin initially denied they were Russian soldiers, then acknowledged they were in a March 2014 documentary.
Crimea Annexation and the Donbas War (2014-2022)
Russia formally annexed Crimea on March 18, 2014, the first time a European nation used military force to seize another’s territory since World War II, per Britannica records.
Key events in the 2014 escalation:
| Event | Date | Key Detail |
| Russian soldiers enter Crimea | February 27, 2014 | No insignia; later confirmed as Russian troops by Putin |
| Crimean referendum | March 16, 2014 | Official result: 97% for annexation; disputed internationally |
| Russia formally annexes Crimea | March 18, 2014 | First European territorial seizure by force since WWII |
| Donbas separatists seize buildings | April 2014 | Russian-backed groups take Donetsk and Luhansk city halls |
| Minsk I Agreement | September 2014 | Ceasefire framework; repeatedly violated within weeks |
| Minsk II Agreement | February 2015 | Second ceasefire; never fully implemented |
| Pre-war death toll in Donbas | 2014-2022 | More than 14,000 killed in eight years of low-intensity conflict |
The US, EU, and their allies imposed economic sanctions on Russia and never recognised the annexation. However, no military response followed. Russia drew a clear lesson: the West would sanction but not intervene militarily to reverse territorial changes.
The Donbas war ground on through both Minsk agreements. Ceasefires were agreed and violated. The front lines froze into a trench conflict that killed more than 14,000 people over eight years before the 2022 invasion.
The Road to War: Russia Massed 150,000 Troops, NATO Rejected Its Demands, and Invasion Followed
Through 2021, Russian troop concentrations along Ukraine’s borders climbed from 100,000 to approximately 150,000. By late 2021, Russian forces were positioned north of Ukraine in Belarus, east along the Russian border, and south in Crimea, surrounding Ukraine on three sides.
In December 2021, Russia issued formal ultimatums to NATO and the US demanding:
- A written commitment that Ukraine would never join NATO
- A withdrawal of NATO military infrastructure from Eastern Europe
- A halt to NATO weapons transfers to Ukraine
Both NATO and the US declined. Putin’s demands were seen in Western capitals as non-starters; in Russian strategic logic, they were described as existential requirements.
On February 21, 2022, Putin recognised the Donetsk and Luhansk “People’s Republics” as independent states. The move created a legal pretext for Russian troop deployment. Three days later, at approximately 5:00 AM on February 24, 2022, Russia launched its full-scale invasion.
Russia’s Full-Scale Invasion: Kyiv Offensive Repelled, ICC Warrant Issued, 141 Nations Condemned It
Russia’s initial strategy aimed for a rapid advance to capture Kyiv within days, topple Ukraine’s government, and install a compliant administration. The strategy failed within weeks.
Ukrainian forces, equipped with Western anti-tank weapons and operating with US and allied intelligence support, repelled the Kyiv offensive. By late March 2022, Russian forces withdrew from the Kyiv, Chernihiv, and Sumy regions. After the withdrawal, the city of Bucha north of Kyiv was found with evidence of mass killings of civilians. The ICC opened an investigation and issued an arrest warrant for Vladimir Putin in March 2023 for the unlawful deportation of Ukrainian children to Russia.
International response to the invasion:
- UN General Assembly voted 141 to 5 to condemn the invasion
- European Union, US, UK, and Canada imposed sweeping economic sanctions targeting Russian banks, energy exports, and individuals
- NATO allies began supplying Ukraine with weapons, ammunition, and financial assistance
- More than 8 million Ukrainians fled the country in 2022, with 5.9 million registered as refugees internationally as of July 2026 per CFR Global Conflict Tracker
Russia refocused its campaign on eastern and southern Ukraine after the Kyiv withdrawal. The war entered a grinding phase across the Donbas front lines.
2023-2026: Attrition, Aid, and No Ceasefire
By 2023, the Russia-Ukraine war had shifted from a war of maneuver into a war of attrition, grinding down both armies at rates not seen in any major conflict since World War II. Ukraine launched a counteroffensive in summer 2023 that recovered some southern territory but did not achieve the sweeping breakthroughs anticipated. Russia pressed forward in Donetsk, advancing at enormous human cost.
Verified War Statistics (as of mid-2026)
| Indicator | Figure | Source |
| Russian military casualties (killed, wounded, missing) | Approximately 1.2 million | CSIS, January 2026 |
| Russian soldiers confirmed killed | Up to 325,000 | CSIS, January 2026 |
| Ukrainian military casualties | 500,000 to 600,000 | CSIS, January 2026 |
| Combined casualties (both sides) | Up to 1.8 million | CSIS, January 2026 |
| Civilian casualties (killed and injured, verified) | Nearly 56,000 | OHCHR / CFR, June 2026 |
| Ukrainian refugees registered internationally | 5.9 million | CFR, July 2026 |
| Ukrainian territory under Russian control | Approximately 20%, including Crimea | ISW / CFR |
| US aid to Ukraine (since January 2022) | $188 billion | CFR, July 2026 |
| EU aid to Ukraine (since January 2022) | $197 billion | CFR, July 2026 |
Russia has suffered more military casualties than any major power in any war since World War II, per CSIS analysis published in June 2026. An Easter ceasefire announced in April 2026 was violated 2,299 times within 48 hours, including 747 drone strikes, per Ukrainian armed forces data. Ceasefire negotiations mediated by the Trump administration through 2025 and 2026 have produced no lasting agreement as of mid-2026.
The war enters its fifth year with no clear end in sight. Every power plant in Ukraine has sustained damage. Ukraine’s electricity generation has fallen from 33.7 gigawatts at the war’s start to approximately 14 gigawatts. The human and infrastructure cost has compounded with each passing year.
Frequently Asked Questions
When did the Russia-Ukraine war actually start?
The conflict began in February 2014 when Russia annexed Crimea and backed separatists in Donbas, killing more than 14,000 people over eight years. Russia launched its full-scale invasion on February 24, 2022, marking Europe’s largest armed escalation since 1945.
Why did Ukraine give up its nuclear weapons?
Under the 1994 Budapest Memorandum, Ukraine surrendered its nuclear arsenal (the world’s third-largest, approximately 1,900 warheads) in exchange for security assurances from Russia, the US, and the UK, pledging to respect Ukraine’s territorial integrity and borders.
What were the Minsk Agreements and why did they fail?
Minsk I (2014) and Minsk II (2015) were ceasefire frameworks between Ukraine and Russia-backed Donbas separatists. Both were repeatedly violated and never fully implemented, leaving a low-intensity front-line conflict that continued until Russia’s 2022 full-scale invasion.
How much Ukrainian territory does Russia control in 2026?
Russia controls approximately 20% of Ukraine as of mid-2026, including Crimea annexed in 2014 and portions of Donetsk, Luhansk, Zaporizhzhia, and Kherson oblasts. Russia gained around 1,897 square miles of additional territory in the 12 months to April 2026 per ISW data.
What is the ICC arrest warrant for Vladimir Putin?
The International Criminal Court issued an arrest warrant for Vladimir Putin in March 2023 for the unlawful deportation of Ukrainian children to Russia, a war crime under the Rome Statute. The warrant remains active and unenforced as of mid-2026.
How many people have been killed in the Russia-Ukraine war?
Russia has suffered approximately 1.2 million casualties (killed, wounded, missing) per CSIS January 2026 estimates. Combined Russian and Ukrainian casualties could reach 1.8 million. Nearly 56,000 civilian casualties were verified by OHCHR as of June 2026.
