Ukraine crisis: How strong are Ukraine's ties to Russia?
17 April 2014 Last updated at 00:12 BST
Ukraine, whose name means 'borderland', has a long history with the Russian Federation.
As part of the Soviet Republic, many Russians settled within its borders. But how strong is pro-Russian sentiment there now?
Newsnight's Diplomatic Editor Mark Urban looks at how the country's borders have changed since 1922, and assesses what could happen next.