Nice scenario Jest.
I'll change just one thing. I would imagine the terrorists to be, for exemple Pro-Russian Ukrainian (why not Crimean independentists) with strong but no direct ties with Moscow (There are several other possible choices).
Then, with the already numerous dead in the former Pact countries of the EU, the situation might quickly become tense. European countries might roll the tank first in support of Ukraine (trying to crush these terrorists) and it might extend its support to Georgia again. It would also offer membership to these countries in the EU. As a result, Russia would have to respond.
Then, the Russian can roll the tanks in response to Ukrainian military operation in Crimea. In the meantime, they would establish a free Crimea, reinforce their position in the Caucasus (why not even moving against Azerbaijan). At last they might also attempt to establish a puppet government in Ukraine. As a result, EU, fearing for its energy supply will take that opportunity to declare war.