Situation in Ukraine

[Rudy Tamasz]

Keeping access to a permanently unfrozen port has been a core part of Russian policy for 200+ years. They've been to war with Britain and France over the Crimea over Sevastopol, with Japan over Port Arthur and attempted to secure Afghanistan and later Iran bringing them into conflict with Britain again to get access to the Indian ocean right up to 1945.

This is a pretty good summary of how Russians see the international politics. The problem is, while they are firmly stuck in realpolitik 19th century style, it's 2014 and what had been reasonable back then is not necessarily a good idea now.

I think the EU/USA would have been naive if they had imagined that Putin wouldn't interfere

Russian are stuck in 19th century, but EU/USA are stuck in early 1990s when they pretty much ruled the world and things were going their way. Not anymore, they might be in for a few surprises, too.