The significance of the annexation of Crimea by Russia goes far beyond land territorial claims. Here are a couple of maps that show how Crimea affects oil rights in the black sea.
Black Sea Claims Before Crimea Annexation
Black Sea Claims After Crimea Annexation
The above charts from the New York Times article In Taking Crimea, Putin Gains a Sea of Fuel Reserves.
Russia did not annex Crimea just because of Black Sea claims. But, those claims make it all the more unlikely that Russia would ever cede Crimea back to Ukraine under any circumstances.
Moreover, Russia has no land connection to Crimea, and Russia has every reason to want to end that situation.
If you are looking for another reason for the rebel counteroffensive “march to the sea”, you now have one.
Mike “Mish” Shedlock