It is difficult to make a substantial contribution along the lines of argument in the present analysis. In this limited volume it provides a really thorough and in-depth insight into the highly entangled and opaque situation in-between the two heavy weight descendants of the Soviet Empire. Given this, I would like to suggest a somewhat different perspective.
The Ukrainian crisis and its Crimean exasperation is only a brink in the chain of post-soviet „succession wars“ - remember Nagorno-Karabakh, Ossetia, Abkhazia, Transnistria, ... One would never understand the true nature of these conflicts without a glance into the pre-soviet and soviet history of the former Russian empire and Soviet territories. The status quo is a very popular argument when it comes to decisions about border lines. One forgets however how arbitrary the drawing of the border lines of the early and not so early Soviet Union was. Stalin's or Khrushchev's whim sufficed to put whole populations on this or that side of a newly drawn line on the political map. Whole autonomous republics were dismantled within a night (the Republic of the Volga-Germans in 1941), the Crimea changed hands in 1954 when Khrushchev passed it from Russia to Ukraine. It is perhaps the most deplorable moment of the collapse/dissolving of the Soviet Union that one didn't try, to at least partially compensate for those chaotic policies, by redrawing within the still existent late soviet legitimacy the most obvious cases of misplaced border lines. Gorbachev just did not (want to) think of that.
Now - what is more important - the preservation of the present course of border lines inherited from the ghosts of a Stalinist past or the well-being of whole populations whose ethnic, cultural and emotional allegiances definitely come into conflict with those borders? Along the same line of reasoning, the West, trying to intervene, should be aware of its own inglorious heritage when it comes to redrawing existing borders – take Kossovo as a most lamentable case of the near past.
Instead of resolving to nationalist rhetoric and worsening the ongoing showdown wouldn't it be wise of the interim government in Kiev to seek for a negotiated settlement of the fundamental ethnic and natural resources problems in the areas of strongest confrontation between both countries. To avoid either party being bamboozled, the EU could step in as a mediator. Provided, of course, that it manages somehow a balance in which Russia doesn't come too short.