Russia has been conducting military exercises with 45,000 combat troops on the eastern border of Ukraine since March 13, destabilizing the eastern part of the country and stoking fears in Kiev of an imminent invasion. The map below is based on a paper released by the Royal United Services Institute in April that details which Russian units have been mobilized and where they are operating. Further analysis by The Washington Post shows where these Russian units have come from and what portion of Russia's regionally available combat forces have been shifted to the Ukrainian border. Related story.
For the rest of the story: http://apps.washingtonpost.com/g/page/world/russias-buildup-on-the-ukraine-border/996/