The responsibility for the Russia-Ukraine war is complex and debated, but several key factors and actors contributed to the conflict:

Russia and Vladimir Putin bear primary responsibility for initiating the full-scale invasion of Ukraine on February 24, 202212. Putin ordered Russian troops to invade Ukraine in what he called a "special military operation," launching attacks across the country2.

However, tensions and conflict between Russia and Ukraine predate the 2022 invasion:

1. The crisis began escalating in 2014 when Russia annexed Crimea from Ukraine and supported pro-Russian separatists in eastern Ukraine's Donbas region36.

2. NATO's 2008 announcement that Ukraine and Georgia "will become members" was seen by Russian leaders as an existential threat1. Putin and other Russian officials had long opposed NATO expansion toward Russia's borders.

3. The 2014 Euromaidan protests in Ukraine, which ousted pro-Russian president Viktor Yanukovych, were viewed by Putin as a Western-backed "fascist coup"4.

4. Some argue that Western powers, particularly the United States, bear some responsibility for pushing policies that Russia perceived as threatening, such as NATO expansion1.

5. Historical factors, including Putin's view of Ukraine as not a legitimate independent state, also played a role in his decision-making5.

It's important to note that while various factors contributed to tensions, Putin made the decision to launch a full-scale invasion in 2022, an action widely condemned internationally as a violation of international law23. The invasion has resulted in significant loss of life, displacement of civilians, and global economic impacts.