Ukraine's civil war started on 2 May 2014, when supporters of the February-coup-imposed (click on that link if you don't know about that coup) Ukrainian central government firebombed Odessa's Trade Unions Building, incinerating hundreds of Odessans who opposed the coup.
This civil war is of massive historical importance, because it re-starts the global Cold War, this time no longer under the fig-leaf rationalization of an ideological battle between "capitalism" versus "communism," but instead more raw, as a struggle between, on the one hand, the U.S. and West European aristocracies; and, on the other hand, the newly emerging aristocracies of Russia and of China. Like had happened in World War I, this global war is between two contending aristocratic alliances. (That's the standard thing, we historians know; it's nothing unusual there.) However, the documentation of the history is much clearer and far faster for this new war, than for former global wars, regarding which of the two sides had really initiated it, and why.
The "players" in "The Great Game," this time around, are, broadly speaking, West versus East; those are the two contending "teams," of aristocracies. USA is the leading participant on the western side, and has the backing of Europe's aristocracies via the IMF; and Russia is the leading participant on the eastern side, and has wrangled the backing of China's aristocrats. The West is far better-funded than the East, and, so, this is a war that the East did not want, and had hoped to avoid, but that has been thrust upon them, by the Obama-initiated coup that took place in Ukraine during late February 2014, and also by the Obama-initiated massacre that occurred in Odessa on May 2nd (the event that immediately sparked Ukraine's civil war).
As I have previously documented, Obama is knowingly falsifying (he's lying), when he claims that Ukraine's civil war is wanted and was initiated by Putin, and that Obama didn't want and initiate it via the February overthrow. I also have explained, by use of charts and graphs, the broader background, "How and Why the U.S. Has Re-Started the Cold War (The Backstory that Precipitated Ukraine's Civil War)."
The only thing that's additionally needed, in order for a reader to be able to understand the origin of Cold War II, is a 12-page article by Mary Elise Sarotte, published in the January 2010 journal of The Society for Historians of American Foreign Relations, Diplomatic History, which is titled, "Not One Inch Eastward? Bush, Baker, Kohl, Genscher, Gorbachev, and the Origin of Russian Resentment toward NATO Enlargement in February 1990."
Sarotte describes there how the then-Soviet leader Mikhail Gorbachev, desperate to end the Cold War so that his nation could begin recovering from 70 years of Marxism that had followed upon centuries of feudalism, tried his best to get U.S. President George Herbert Walker Bush to not take advantage of the economic and increasingly also military weakness of Russia -- not to expand NATO and U.S. missile-bases into the formerly Soviet nations bordering Russia: Estonia, Latvia, Belarus, Ukraine, Georgia, Azerbaijan, and Kazakhstan. He also didn't want missiles in nearby-but-not-adjoining Norway, Finland, Poland, Czechoslovakia, Hungary, Bulgaria, Romania, Yugoslavia, and Germany.
However, he was especially urgently concerned about Germany, because the Berlin Wall had just fallen, on the evening of 9 November 1989; so, Russia was certainly going to be losing its former control of Eastern Germany. Since Gorbachev was the supplicant here, he left only till the very end of the negotiations the broader, less-urgent, issue of non-expansion of NATO and of NATO missiles into other former-Soviet states adjoining the ones adjoining Russia.
Almost the entirety of the negotiations until the very end concerned Germany, because the immediate crisis was that. At first, West Germany's Chancellor Helmut Kohl was sympathetic to Gorbachev's broader security concern; but, "in the course of the Camp David meeting at the end of February he came to agree with the Bush position: simply a special military status for the GDR [German Democratic Republic -- East Germany -- no missiles there, but] not general assurances about NATO's territory [her euphemism for NATO's enlargement to Russia's doorstep]. The chancellor agreed with the president despite the fact that this was not what he had discussed with Gorbachev two weeks earlier [her euphemism for the probability that Kohl switched his position on that issue after further consultations with his American master]." Kohl was directly dependent upon assistance from the U.S. aristocracy (to be paid for by the U.S. taxpaying public, not by the aristocrats who actually control the government), in order for West Germany to be able to absorb the wrecked economy of East Germany without enserfing the East Germans to such an extreme extent that a German civil war would be the ultimate outcome. The senior Bush, apparently, demanded that Kohl comply with his aim to expand NATO, up to Russia's doorstep.
President Obama's coup in Ukraine is an important part of that 1990-initiated program, and (as the articles that I earlier linked to have documented), he's being supported crucially in this by the IMF, which represents not only American aristocrats but also west European ones; and (as also was linked there) the Bilderberg meeting, that was just completed, was very much concerned with the civil war in Ukraine, for which reason the IMF's chief Christine Lagarde was there, and not only David Petraeus, Lawrence Summers, Robert Rubin, Eric Schmidt, oil-company presidents, and other members and servants to the aristocracy, regardless of which particular side of their respective revolving doors into and out of government (AKA: international corporations and their "charities") they might happen to be at the moment. (National heads-of-state know better than to come, and the organizing committee for these meetings knows better than to invite them there. Their attendance would raise too many uncomfortable questions in a "democracy.")
Lots of people in southeastern Ukraine, as the bombs are raining down on them from Blackwater (now called 'Academi') mercenaries and the Kiev Government, are shocked and enraged that Putin hasn't sent in Russian tanks, but the Russian leader knows that doing that would be exactly what the propagandists in the West are hoping for, in order to provide a pretext for Western governments overtly to provide troops and materiel to the Kiev central government, and really expand this thing.
As I have formerly documented (see those links), the reason for this operation against Russia is basically to preserve the dollar as the world's reserve currency. If Putin can hold out long enough, the dollar will collapse and so will the U.S. economy; but it's probably going to happen anyway, and so the longer that Putin remains "weak" against the U.S. assault, the sooner will come that likely U.S. collapse. This will thus be a war of nerves between Obama and Putin: Obama, to hold off the U.S. collapse; and Putin, to prevent a Russian collapse.
These sorts of wars don't do anybody any good except some bankers and war-profiteers, but Obama is smart enough to have known at the start that he was rolling very big dice here, and he seems to have thought that the bigger the stakes are, the likelier it would be for the U.S. aristocracy to emerge on top. Future historians will likely have a field day trying to figure out how he came to these bold conclusions; but, if Obama wins, then probably everybody will know how and why, and we historians will have other work to do.
If Obama loses, then Putin might remain quiet simply because of the difficulty he'll have explaining to the Russian people why he had held back for so long while the Russian-speaking Ukrainians next door were being slaughtered. Even if Putin wins, he'll probably lose in public esteem. Like I had said: this isn't a war he wanted.