"Without Ukraine, Russia ceases to be a Eurasian empire. Russia without Ukraine can still strive for imperial status, but it would then become a predominantly Asian imperial state, more likely to be drawn into debilitating conflicts with aroused Central Asians, who would then be resentful of the loss of their recent independence and would be supported by their fellow islamic states to the south. China would also be likely to oppose any restoration of Russian domination over Central Asia, given its increasing interest in the newly independent states there. However, if Moscow regains control over Ukraine, with its 52 million people and major resources, as well as its access to the Black Sea, Russia automatically again regains the wherewithal to become a powerful imperial state, spanning Europe and Asia."
- Zbigniew Brzezinski, on page 92 of the Grand Chessboard, 1997, a book whose main thesis is that the US "must perpetuate [its] own dominant position for at least a generation and preferably longer" (quoted on backcover), in the world, and therefore on its strategically most important continent, Eurasia, where "it is imperative that no Eurasian challenger emerges, capable of dominating Eurasia and thus also of challenging America" (p. xiv). Brzezinski was National Security Adviser in the late 1970s and boasted (in an interview with Nouvel Observateur magazine in 1998) that US intervention in Afghanistan at that time had drawn the USSR into an unwinnable war. He found this entirely justifiable, since it undermined the Soviet Union, regardless of the human costs to Afghans, Russians and others (thus displaying the same moral - i.e. immoral - stupidity as supposed leftists who now joyfully chant 'George Bush, Uncle Sam, Iraq will be your Vietnam').
All of which is just to say that Brzezinski is an extremely immoral agent, an man who acted to preserve and deepen US global hegemony not despite the suffering caused, but absolutely regardless of it. He is also well-informed, intelligent and generally realistic (he is not a neo-con like Wolfowitz or Perle). So what he says about Ukraine may be worth our attention.
Brzezinski classes Ukraine as a geopolitical pivot (along with Azerbaijan, Turkey, South Korea and Iran). These are "states whose importance is derived not from their power and motivation but rather from their sensitive location and the consequences of their potentially vulnerable condition for the behaviour of geopolitical players" (p. 41). That is, they are the vital squares on the 'Eurasian chessboard', control over which will improve the position of the only real players, countries like the US, Russia, China, France and Germany, whose 'reach exceeds [their] grasp' (p. 40, quoting Robert Browning).
Brzezinski's thesis makes some sense of the concentrated focus on the Ukrainian election - and subsequent popular revolution - from Russia on one side and the US on the other, with both 'players' making resources available via front organisations like (on the US side) Freedom House. It is worth noting in passing that Russia's involvement on the side of Yanukovitch had them supporting the chosen successor of Kuchma, a politician who had made his country's independence from Russia clear and thereby encouraged independent action among smaller post-Soviet states. Russia was fighting a rearguard action, in other words. The US, on the other hand, is pushing forwards, and with its military bases in Central Asia since late 2001 (after Brzezinski was writing) is leaving Russia with no sphere of influence. (But see this Japan Focus article about the multi-billion dollar China-Iran gas deal for argument that the situation in Central Asia is multipolar - between the US, China, Russia and Iran, I suppose, in order from global to regional players.)
One might wonder if Russia would try to project power in North-East Asia since it is blocked to its west and south. I doubt that it has the ability to do this. Those who still see things, inadvertently, in Cold War terms, should note that, as President Roh of South Korea says, it is China which is sustaining North Korea, wishing to avoid the consequences of its collapse. The most influence Russia has been able to bring to bear on the region is probably in ongoing negotiations over whether a gas pipeline will go to China or to the Russian coast near to Japan. Nonetheless, it is likely that loss of influence in a key state on Russia's west side will have implications for Russia's objectives and policies on its other borders.