There might be more to the anti-austerity vote than meets the ballot box. The anti-austerity vote might well be a protest against the political establishment that is being held responsible for throwing the country into the deep crisis it is currently in.
The European Union matters deeply but the people of Europe do not want federalism. Not yet, anyway. The beginning of political wisdom is to respect that, back off, listen to the people, and build the Europe they do want, from the bottom up. What is at stake is much more than the European project; it is the credibility and principle of democracy itself.