Putin decided to intervene in Crimea, protecting the pro-Russian populace in that region. The two countries share an intense history between them. When the USSR fell in 1991, Ukraine was formed as an independent state, however the Russian influence on its eastern side still remained. The Russian soldiers and the pro-Russian militias have taken control over major Government buildings in Crimea as well as couple of military bases. Putin’s bold decisions have alarmed the EU and the Americans, as this certainly is a cause for concern.
“Russia's Foreign Minister Sergei Lavrov has warned the US not to take "hasty and reckless steps" in response to the crisis in Ukraine's Crimea region.” - BBC
Moscow justifies this invasion as an act of protection of the ‘Russians’ living in Crimea. Nevertheless, Russia has stunned the Western countries. Ben Juddah’s article on Politico titled “Why Russia No Longer Fears the West”, gives an interesting insight to why Putin’s confidence has led Russia to take such bold decisions. It’s about time that Russia has realized that the mindset of nations has changed since Cold War. The Western nations are all about the money and President Yanukovych’s decision of standing beside Russia undermines the importance of the EU heavily.
Matters might get worse or out of hand, however as long as the guns are kept aside, the situation can be controlled. For some this seams as a breach of Ukraine’s independence, for others it is an act of protection of their own people in Ukraine. US has intervened into many scenarios themselves however this time Russians chose to beat them to it. US can’t always be the savior, or maybe that is what concerns the Americans. Americans and the EU don’t want to give appeasement a chance this time, because last time it resulted into WWII.