But anyway, this is not a case of ethnicity v/s ethnicity --> Ruthenians and Muscowites are ethnically nearly the same. It's more about a way of thought/life -- you can compare the differences to that of the Czechs and Slovaks (not completely, but similar) -- the Ukrainians never developed a centralised mono-culture like their Russian or Polish neighbors.
I believe, that is the right way to look at it. The Russians, even conservative, anti-Soviet Russians, used to think in ethnic terms, viewing Ukraine too close ethnically to ever break off. They viewed the 1991 referendum as somehow aberrant. The Maidan stunned them. Some now call for Czechoslovakia-style armed invasion, putting their anti-Sovietism on the back burner.
Indeed: Ukraine as a whole, more so in the West but also in the East, is making a civilizational choice for Europe. It is not the Europe of regulated cheese and tomatoes, not the Europe celebrating homosexuality, but the Europe of Charlemagne, Aquinas and Beethoven. The feel that with Russian Federation sucking them into some kind of Asiatic swamp, the time is now or never.
I doubt the wider Moslem world would help the Ukrainians against the Russians.
Islam exists in two modes: when they are distant minority they whine and appeal to our best instincts of compassion; then when the numbers are right, they pull the Kalashnikovs out. At this point, at least, the Tartars are used tactically by Kiev, as a backstop in case Crimea really decides to secede. If Putin were smarter, he could use them too, as an example of Ukraine's multi-ethnicity, and call for federalization. An ethnically Russian federal constituent republic of Donbass inside Ukraine is really the most he can achieve, perhaps at the price of seeing the Crimea run by the Tarter Mejlis.
By the way, Kadyrov -- the Chechen leader -- is supporting the Russians, whom he "loves dearly", although it is possible that he was not sober at the time.