Naturally fascism isn't going to die, just as all forms of government, in theory, won't die. So long as the idea remains, some people are always going to be attracted to it. However, the notion of the world slipping back into barbarianism makes for a decent imagination and nothing else.
Radical forms of government typically form when there's desperation. Communists, for example, overthrow the czar in Russia because of the severe number of troops killed in World War I, as well as mounting tensions back home. Germany went fascist after the treaty of Versailles decimated the nation and their pride; Hitler's goals and ideals were just the thing that Germans needed to restore their once great nation. They were desperate for change and voted in Hitler using the ineffectual democracy of the Weimar Republic to do so. To me, it makes no difference whether Hitler seized power, as one can argue he later did, or was democratically elected; people were desperate for change and turned to radical government.
I won't deny that I know jack all about the state that Greece is in, but I hardly assume it's teetering on the edge like Russia in 1917 or post-WWI Germany. 4% still isn't a terribly large percentage, and when going back at least in American history, that's consistently what the American Communist Party got between 1890 and 1928. If, after reading this, I tell you there was a surge in votes for both the Communist and Fascist parties during the Depression, you really shouldn't be surprised. I believe there's actually a famous picture on the cover of Time that shows a fascist parade in front of Capitol Hill.
There was one thing I found interesting, though, and that was the demographic of 18-30. The last fascist in power was Francisco Franco in Spain, and he died in 1975, 32 years ago. It's similar to the rise in communist beliefs I've seen over the last few years, except the demographic only goes to 25. Basically, these people would be the first generation who wouldn't have a fear of communism stuck in them when they were older because by the time they were old enough to understand, the Soviet Union had collapsed.
In conclusion, no, I don't think the world is slipping into barbarianism.