The initial cause of those protests was the rejection of the government of further EU agreements, in favour of greater economic co-operation with Russia; the deeper reason was endemic corruption of the governing administration.
On one side, there is the incumbent (pro-Russian) government, supported by Russia; on the other, are the "pro-European" (and pro-EU) opposition, backed by the EU and the USA.
Now the situation has turned to armed violence in the centre of Kiev, with the situation unravelling in the regions, especially those dominated by the largely Ukrainian-speaking opposition in the west and north. Even Crimea, an ethnically Russian region on the Black that also hosts Russia's Black Sea fleet, has threatened to secede and join Russia if things get much worse.
On the one hand, the West has decisively thrown its lot in with the opposition, supporting sanctions against the government; on the other hand, Russia has decisively thrown its full support behind the government (what that means precisely at this stage is unclear), calling the opposition "fascists", and the EU's demands "blackmail".
Seen through a Russian lens
Ukraine broke away from Russia (then the Soviet Union) a little over twenty years ago, but Russia has only really took Ukraine as being nominally independent ever since. The reasons for this are cultural and historical; regardless of what Ukrainians (Russian-speaking or not) may think of it, the Russians still consider Ukraine to be firmly part of Russia's sphere of influence.
Apart from Ukraine and the break-up of the former Soviet Union twenty years ago, Russia's perspective on the current Ukraine Crisis must be considered in relation to recent actions in Russia's back-yard, and areas of Russian influence in general.
From this point of view, we must go back to the Balkans. The break-up of Yugoslavia in the early 1990s and the wars in Bosnia and Kosovo resulted in the collapse of the Milosevic government in Belgrade, Russia's last firm ally in the Balkans.
Moving on to the 21st century, you had the Orange Revolution in Ukraine in the middle of the first decade, as well as the Rose Revolution in Georgia, both bring pro-Western governments on to Russia's doorstep. Regardless of the exaggerated Russian paranoia at these events, these both happening only a couple of years after their neighbouring Baltic States has joined NATO (as a result of the "War On Terror"), it meant that Russia had very few "friendly" nations left around it.
Furthermore, with China rapidly growing in stature, Russia had also lost economic influence in Central Asia; and the USA was using the "War On Terror" to utilise military bases in places like Uzbekistan. By this point, Russian paranoia of "encirclement" begins to gain an element of credence.
Things began to hot up in 2008. Early in that year, Kosovo declared independence from Serbia, Russia's one-time ally. Russia supported Serbia's protests, and in the end only a modest number of countries recognised the new nation's sovereignty.
However, Russia got its own back soon afterwards, by unilaterally accepting the independence of two breakaway (Russian-speaking) regions of Georgia; then when the pro-Western Georgian President, Saakashvili, ordered the "reclaiming" of those two regions while Vladimir Putin was watching the opening ceremony of the Beijing Summer Olympic Games, Russia had reason to believe they were being taken for fools, regardless of Saakashvili's claims of Russian provocation. A brief war led to those regions being kept firmly from Georgian control, with the West unwilling to directly intervene; only Russian restraint, under pressure from the West to cease hostilities, allowed Saakashvili to remain in power.
The "Arab Spring" that began in early 2011 brought another challenge to Russia's "perspective" on the world. During the Cold War, the Middle East has been as much a battleground for influence has any other part of the world, and Russia's friendly relations with Syria (and Russia's naval base on the Syrian coast) have been the still-fruitful product of that.
The UN-backed war against Libya in 2011 was considered a dastardly trick by the West on Russia, hoodwinking them into backing what would ultimately be the collapse of the anti-Western (and implicitly, pro-Russian) government of Gaddafi.
Thus, last summer, when the US, France and the UK supported military action against the savage crimes of the Syrian (pro-Russian) government during its ongoing civil war, Russia did everything it could to prevent it from happening, successfully keeping their sole remaining ally in the Middle East from harm.
Russia's geopolitical positioning since the end of the Cold War has been to promote the status quo in the developing world, and non-interference in the internal affairs of other countries. Naturally, this is because it is in Russia's interests to do so. This follows also with relations with Iran, as Russia has been playing its part to be "helpful" to both Iran and the West.
It is from this chain of events that we get a better perspective of Russian thinking. Seen through this lens, Ukraine represents to the Russian administration something more like a "red line" that cannot be crossed. After the perceived humiliations, encirclement and loss of allies in the last fifteen years, Ukraine is Russia's last "big prize", along with Syria. It has naval assets it both countries. The Orange Revolution led to a short-lived pro-Western government; the current (pro-Russian) government replaced it in the following elections.
Politically, strategically and culturally, it cannot afford to "lose" Ukraine.
Russian paranoia about Western-backed "fascists" attempting a coup against the pro-Russian government therefore has a long history to back it up. The timing of the violence, happening during the Winter Olympics in Sochi, would be seen as no coincidence in Moscow; neither would the fact that the US military sent a surveillance boat to the Black Sea to help with "anti-terrorism".
Ghosts of 1914
The hundredth anniversary of the start of the First World War brings back some uncomfortable parallels to the current situation in Ukraine.
It should be remembered that the spark that led to the war starting was in the Balkans: A Bosnian Serb nationalist, backed by elements of the Serbian military and government, killed the heir to Austria-Hungary. Russia supported Serbia, encouraging her to reject the demands of Austria.
What is important here is the role of Russia; without Russia's support, Serbia would likely have given in to Austrian demands (which, incidentally, where modest compared to those that NATO demanded of Serbia/Yugoslavia in 1999; while Austria was looking for a way to humiliate Serbia, it still gave plenty of room for Serbia to wriggle out of war). In this respect, Russia shares a large part of the blame for escalating the situation: first, by telling Serbia to stand up against Austrian aggression; second, by creating the narrative orthodoxy (regardless of the truth) for the reasons for the war in the first place i.e. Austrian aggression, which gave France and Britain a reason to join on Russia's side.
Jump forward a century, and we see much the same narrative played out again, albeit in the theatre of Ukraine and not Serbia, with the West (EU/USA) playing the role of Austria against Russia. Like in 1914, Russia accuses the West of aggression and blackmail with its demands on its ally; and also like in 1914, by Russia encouraging the Ukrainian government to "stand firm" and offering its full support, it risks escalating the situation further.
It should also be remembered that the years preceding the First World War included various "crises" and regional wars; the Balkan Wars of 1912 and 1913, like the unrest in the Middle East since the "Arab Spring" resulted in unpredictable and unstable politics in strategically-important countries.
In this way, we see that Russia's perspective has never really changed; only the situation has.
Where will this lead? Three possibilities offer themselves.
The optimistic scenario:
Government ministers soon withdraw their support from the President, forcing him to do a deal with the opposition. Mediation with both Russia and the West working with both sides to calm the situation. At present, this looks unlikely, at least in the short-term; violence is intensifying as the two camps are drifting apart.
The middling scenario:
Low-level violence continues for some weeks, until ministers tire of the chaos, and encourage both Russia and the West to mediate.
The worst-case scenario:
Civil war erupts, with Crimea seceding. Russia decides to intervene directly to protect its strategic interests, as Ukraine represents its "last line of defence"; the West's response depends on the level of influence that "hawks" have in the EU nations and Washington. Hawks in the West may argue for a strong response after being denied by Russia a "just war" in Syria the previous year.
Although last this scenario looks far-fetched, the psychology of the various players in the West is important; Obama's rhetoric against Russia in the Ukraine Crisis has thus far been (uncharacteristically) very strong. In this way, perhaps the thought of "missing out" on a strike against Syria is playing on his mind?
On such things can wars be decided.
A further analysis of the situation in Ukraine (and Moscow's intentions) can be found here.
A further analysis of the situation in Ukraine (and Moscow's intentions) can be found here.