It seems to me that east of Italy / Germany all of Europe was in the Soviet sphere of influence, with the blatant exception of Greece. I'm sure that the long coast made access to Western influence easier, assuming that Western influence is what the Greek hegemony of the time wanted. But why? Was Greek a failure of Soviet influence? Was Greek a success of Western influence? How much of this can be attributed to internal Greek policy and culture (birthplace of democracy)?
Edit: The Wikipedia article on Greece glosses over the Greek civil war, but having found the page that describes the war in detail the answer to this question resides in there. In short: NATO involvement and lots of dead Greeks. Thanks to Anixx for pointing me in the right direction.