We tend to talk about the conflict in eastern Ukraine as a tale of Russian aggression. That's not inaccurate — but it isn't the full story, either.

It's true Russia took advantage of Ukraine's weakness after massive protests forced former President Viktor Yanukovych out of office a year ago, first by invading and occupying Crimea, and then by backing a violent separatist movement in eastern Ukraine. Putin's aggression helped spark the war, and it has helped prolong it.

But as this video explains, Ukraine was already deeply divided long before the current conflict broke out in the country's east. Those divisions laid the groundwork for the war and have fueled it ever since. It's those divisions that lie at the root of the separatist conflict, and they mean that any solution to the war will need to be political as well as military.

People in the eastern part of the country are more likely to speak Russian, to vote for pro-Russian candidates in elections, and to want Ukraine to stay in Russia's orbit instead of becoming more integrated into Europe. In the west, those trends are reversed: people are more likely to speak Ukrainian, to vote for more pro-European politicians, and to view Russia as threatening and favor greater integration with Europe.

As a result, different regions of the country had very different reactions when Yanukovych decided to abandon a European Union deal last year and forge closer ties with Russia. The protests that eventually forced Yanukovych from office were far more common in the western region of the country than in the east.

Likewise, while people in the western part of the country tended to see those protests as a pro-democracy movement, people in the east were more likely to see them as anti-democratic — a mob forcing a democratically elected president out of office in order to impose their will on the country. That makes the conflict look very different from either side of the divide — and helps explain why the separatists in the east quickly found some local support.

That means any true solution to the conflict needs to address Ukraine's divide, not just Russia's meddling.