It all seemed to start in the distant past, November 2013, when a trade agreement with the EU went south. "EuroMaidan has grown into something far bigger than just an angry response to the fallen-through EU deal. It's now about ousting Yanukovych and his corrupt government." - Lecia Bushak for Newsweek.1

Riots forced Yanukovych to flee on 21 February 2014. On the 26th, Russians started controlling Crimea and the peninsula was "annexed" into the Russian Federation with about a 96% affirmative vote (higher than both Putin's and Hitler's "approval" ratings).

Petro Poroshenko replaced Yanukovych as President of Ukraine on 25 May 2014. Since then, "anti-Fascist freedom fighters" fight what Russia calls the "Kiev Regime" in southern and eastern Ukriane. Russia claims that "Ethnic Russians in Ukraine are under threat."2 despite the fact that the Office of the Spokesperson says "There are no credible reports of ethnic Russians facing threats in Ukraine. ... in Crimea, the OSCE has raised urgent concerns for the safety of minority populations, especially ethnic Ukrainians, Crimean Tatars, and others."2

But there's nothing to do about Crimea since, according to the Foreign Minister of Russia Sergey Lavrov, "Crimea is a part of the Russian Federation. There was, is and can be no negotiations on Crimea."3 though if you look at Donetsk, center of the Donetsk Oblast and rebel held city as well as neighbor of Russia just like Crimea, where, according to the White House, "A large majority of Donetsk residents (65.7 percent) want to live in a united Ukraine and reject unification with Russia."2 it becomes a bit obvious that Crimea is "part of the Russian Federation" in Russia's eyes only.

Though maybe the threat to Crimean minorities is some kind of retribution, I mean "People are dying, international humanitarian law is being violated – recent assessments by the Human Rights Watch are a particular proof of this. This is happening against the backdrop of statements by our Western colleagues that the Ukrainian authorities have all the rights to use all means necessary to defend their sovereignty, territorial integrity and so on."3 and "It is not Russia, but the Kiev regime and its offshore patrons, who are guilty of the growing numbers of casualties among civilians in Eastern regions."4 (Thanks, Sergey).

With how much the Kremlin blames this all on the "chocolate king" Poroshenko (because all confectionary business heads are evil, just look at Willy Wonka and his illegal immigrant work force) maybe the Ukrainian government are the bad guys here, according pro-Kremlin Pravda.ru (on alleged plans to attack a train) "using Ukrainian security forces but then blaming the freedom fighters, as was the case with [Malaysia Flight 17]."5 and first-class nut site whatreallyhappened.com "Crimea and eastern Ukraine do not want to be part of the European Union, do not want to live their lives as debt-slaves to the ECB, and voted for independence ... but the US and EU don't like the idea of citizens of an overthrown government deciding they want nothing to do with that government they did not elect ... and armed the Junta in Kiev with weapons to make war on their own people."6 (please note the later source also has pages on why the Big Bang didn't happen, "A Gallery of Fake Dead Bin Laden's", and the JFK assassination).

Other than the fact that they want to "protect" ethnic russians, Russia is also in this because, according to Lavrov, terms of an agreement made by the "the former opposition, and now the current authorities" were broken through the allegation that "The Ukrainian leaders are not conducting any constitutional reform."3 despite the fact that amendments to the Ukrainian Constitution made in 2004 after the Orange Revolution, which were overturned in 2010 (the same year as Yanukovych took office), were restored7 which shows at least some constitutional reform.

The only real reason Russia (and it must be Russia because, according to the White House, "the seizure of main government buildings in Ukrainian regional capitals Donetsk, Luhansk, and Kharkiv last weekend (April 5-6), these operations bear many similarities to those that were carried out in Crimea in late February"8 and "Russian internet sites openly are recruiting volunteers to travel from Russia to Ukraine and incite violence."2) has to be involved in Ukraine is to seize it, according to John McCain "Russian ambitions are to restore the old Russian Empire."9

I wanted to find some neutral reporting of the topic but I couldn't find anything in the Swiss news. I personally think the only way to end this is to get Rocky to end it, like the Cold War.

1 - http://www.newsweek.com/2014/02/21/kievs-minstrel-street-revolution-245532.html - Kiev’s Minstrel of the Street Revolution
2 - http://www.state.gov/r/pa/prs/ps/2014/04/224759.htm - Russian Fiction the Sequel: 10 More False Claims About Ukraine
3 - http://www.mid.ru/brp_4.nsf/0/E02A06430588548E44257D250057708D - Briefing by the Russian Foreign Minister, Sergey Lavrov, for representatives of foreign and Russian mass media Moscow, 28 July 2014
4 - http://www.mid.ru/brp_4.nsf/0/0447BA62E3794A6A44257D26005A2053 - Comment by the Russian Ministry of Foreign Affairs regarding the continuing anti-Russian sanctions of the United States
5 - http://english.pravda.ru/news/russia/01-08-2014/128197-false_flag_fascists-0/#.U-KlovldVP0 - Another false flag warning in Ukraine
6 - http://whatreallyhappened.com/category/russia?page=1 - Europe finally set to get tough with 'erratic' Putin
7 - http://en.wikipedia.org/wiki/Euromaidan – Euromaiden
8 - http://www.state.gov/r/pa/prs/ps/2014/04/224762.htm - Evidence of Russian Support for Destabilization of Ukraine
9 - http://politicalticker.blogs.cnn.com/2008/08/12/mccain-putin-wants-to-restore-the-old-russian-empire/ - McCain: Putin wants 'to restore the old Russian empire'

Additional Sources:
http://en.wikipedia.org/wiki/2014_pro-Russian_unrest_in_Ukraine - 2014 pro-Russian unrest in Ukraine
http://en.wikipedia.org/wiki/2014_Crimean_crisis - 2014 Crimean crisis
http://www.mid.ru/brp_4.nsf/0/52256A9F1582BA5344257D1D001E9451 - Exclusive interview given by the Russian Foreign Minister Sergey Lavrov to Russia 24 TV-channel, Moscow, 18 July 2014
http://www.whitehouse.gov/the-press-office/2014/04/28/statement-press-secretary-ukraine - Statement by the Press Secretary on Ukraine