conflict-and-security

Russia Started the War in Ukraine: Key Facts and Background

On 24 February 2022, Russia started a full-scale invasion of Ukraine, marking the largest attack on a European country since World War II. The decision followed years of politic...

Mara Ellison
Russia Started the War in Ukraine: Key Facts and Background

Why Russia invaded Ukraine in 2022: core facts

On 24 February 2022, Russia started a full-scale invasion of Ukraine, marking the largest attack on a European country since World War II. The decision followed years of political tension, military buildup, and Russian claims over territories and spheres of influence. This explainer outlines when and how the war began, the major escalations before and after 2022, and the ongoing status as of early 2025. It is designed as an evergreen reference to help readers understand the conflict’s origins and key milestones.

Pre-invasion buildup: warnings and diplomatic failure

Long before Russian troops crossed the border, Russia had massed forces on Ukraine’s borders and issued demands aimed at rolling back NATO enlargement. Western governments warned of a possible invasion and offered diplomacy, but mutual distrust and competing security narratives prevented agreement. In the months preceding 2022, Russian state media and officials framed Ukraine as an existential threat and denied Ukraine’s right to choose its alliances. This section explains the diplomatic breakdown and why deterrence failed.

Key flashpoints before February 2022

  • Crimea annexation in 2014 and the establishment of Russian-backed authorities in parts of eastern Ukraine.
  • Large military exercises near Ukraine and movements of troops and short-range missiles to Belarus and southern Russia during 2021–2022.
  • Recognition of separatist-held regions in Donetsk and Luhansk on 21 February 2022, followed by the formal invitation for Russia to ‘peacekeep’.

When Russia started war operations: timeline of the invasion

Russia started war operations in the early hours of 24 February 2022, launching missiles against Kyiv and other cities and moving ground forces from Belarus, Crimea, and the east. The Kremlin described the campaign as a ‘special military operation’ aimed at demilitarization and denazification, claims rejected by Ukraine and most of the international community. Below is a concise timeline of the first weeks, with estimated troop numbers where available.

Date or Period Event Why It Matters
24 Feb 2022 Full-scale invasion begins; missiles hit Kyiv and other targets. Marks the start of large-scale war; civilian and military casualties rise sharply.
Late Feb–March 2022 Russian forces approach Kyiv, but fail to capture the city. Ukraine’s resistance and Western support blunt the initial thrust; Russian forces retreat from northern areas.
April–August 2022 Shift to the east: battles in Donbas, capture of Mariupol. Conflict becomes concentrated in Donetsk and Luhansk; humanitarian toll in besieged cities grows.
September 2022 Russian annexation referendums in occupied territories. International rejection; expansion of claimed Russian territory.
October 2022–2024 Protracted frontline warfare, missile and drone campaigns, mobilization cycles. War settles into attritional phases; sanctions and aid shape the battlefield and economies.
2025 Continued fighting with fluctuating frontlines; stalled diplomatic talks. Conflict remains unresolved; humanitarian and geopolitical consequences persist.

Geographic scope and fronts

The war is not limited to one line. Russia started war activities on multiple fronts, including northern Ukraine toward Kyiv, the east in Donbas, the south around Mariupol and Crimea, and intensified strikes on energy and infrastructure far from the frontlines. Understanding the geography helps explain why the conflict has endured.

Main fronts as of early 2025

  • Donetsk and Luhansk (the Donbas): prolonged ground engagements around towns and villages.
  • Zaporizhzhia and Kherson regions: riverine and positional warfare along the Dnieper.
  • Kharkiv and Sumy oblasts: periodic incursions and cross-border shelling.
  • Crimea and Black Sea: drone and missile campaigns; naval incidents.
  • Deep-strike targets: energy facilities and logistics hubs across Ukraine.

International response and impact

When Russia started war in Ukraine, the global community responded with unprecedented sanctions, humanitarian aid, and military support for Kyiv. Organizations have documented severe impacts on civilians, economies, and global markets. While NATO members and partners have avoided direct combat, they have supplied weapons, intelligence, and funding. This assistance aims to sustain Ukraine’s defense while containing escalation risks.

Current status and what to watch

As of early 2025, Russia controls parts of four Ukrainian oblasts and continues limited offensives in the east. Ukraine retains control of most territory but faces challenges in manpower and ammunition supplies. Diplomatic channels remain partially open but inconclusive. Indicators to monitor include ceasefire discussions, Western aid levels, mobilization trends in both countries, and risks of escalation beyond Ukraine’s borders.

Conclusion

Russia started the war in Ukraine with a large-scale invasion on 24 February 2022, building on earlier annexations and confrontations. The conflict has since evolved into a protracted war of attrition with significant humanitarian, geopolitical, and economic consequences. This overview provides a durable, fact-focused foundation for understanding when and why the war began and how it has developed to date.

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