February 28, 2014

The focus of the crisis in Ukraine has shifted from Kiev to the Crimea region, as Ukraine accuses Russia of carrying out an armed invasion by sending naval forces to occupy Sevastopol airport.

Another Crimean airport, Simferopol, has also been occupied by armed men, thought to be pro-Russia militia.

The majority Russian-speaking Crimea region is of political and strategic significance to both Russia and Ukraine.

Russia's Black Sea Fleet has its historic base at Sevastopol. After Ukraine gained independence, a leasing agreement was drawn up to allow the fleet to continue operating from there.

In 2010, this lease was extended to 2042 in exchange for Russia supplying discounted natural gas.

Crisis overview

The crisis began in November 2013 when President Yanukovych's cabinet announced that it was abandoning an agreement that would strengthen trade ties with the EU. The government later sought closer co-operation with Russia.

Anti-government protesters, who supported closer ties with the EU, called for the resignation of President Yanukovych and early elections.

Kiev's central role

There were protests across the country, but Kiev's Independence Square was at the heart of protests for three months.

Although peaceful for most of the time, bouts of violence injured hundreds and left more than 80 people dead.

As the violence escalated, the Ukrainian parliament voted to overthrow President Yanukovych and he fled over the border into Russia.

But the divisions within Ukraine go back much further than recent events. The country has been torn between East and West since the collapse of the Soviet Union in 1991 and this is reflected in a cultural and linguistic divide.

Russian is widely spoken in parts of the east and south. In some areas, including the Crimean peninsula, it is the main language.

In western regions - closer to Europe - Ukrainian is the main language and many of the people identify with Central Europe.

This division is to some extent reflected in voting patterns. The areas where a significant proportion of people speak Russian almost exactly match those that voted for Mr Yanukovych in 2010.

EU and Russia

Ukraine has economic ties to both the European Union and Russia.

Russian gas pipelines to Europe pass through the country - a fact made abundantly clear in 2006 when Russia briefly cut supplies, sparking alarm in Western Europe.

The recent moves to reach a trade agreement with the EU again fuelled tensions with Moscow, which regards it as a step towards eventual EU membership.

Russia would prefer to halt Ukraine's closer integration with Europe in favour of boosting its own influence via a customs union.

http://www.bbc.com/news/world-europe-26387353