STORIFY: The Twitterverse weighs in.
MasterCard and Visa freeze credit card services in Russia.
Read more...Vladimir Putin with Vladimir Konstantinov, Sergei Aksyonov and Alexei Chaly (Image via @KremlinRussia_E)
Russia and U.S. fight sanctions with sanctions, and Sen. McCain laments his spring break.
Read more...Putin restores "history" and adds Crimea to the map of Russia.
Read more...A Ukrainian soldier stands guard during a field training exercise at Rapid Trident 2012 in Yavoriv. (Flickr/U.S. Army Europe)
Putin declares Crimea part of the Russian Federation after "free expression" of will.
Read more...95 percent of voters support leaving Ukraine, but the U.S. and E.U. will not recognize the vote.
Read more...WATCH: What will Obama do to stop Russia's invasion of the Ukraine?
Read more...Putin puts on a show for reporters amidst rising tensions in Crimea.
Read more...WATCH: Russia's UN representative presents letter allegedly authorizing military invasion of the Ukraine.
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