Writing in Spiegel Online International, Wolfgang Kaden offers stern medicine for the present Greek crisis.  His thesis is stated at the outset:

It’s time to reinstate national autonomy—and responsibility—for determining financial policies and honoring treaties.

He goes on:

The euro has been a major experiment.  A (current) total of 17 countries with many things in common—but also many differences, such as their economies, politics, histories and ways of life—have embraced a common currency.  Contrary to the expectations of many (including myself), these differences have not grown smaller over the years.  Unfortunately, there is no reason to expect that such increased harmonization might occur in the foreseeable future.

And

…it appears entirely unlikely that European populations could be willing to, for example, relinquish their parliament’s right to make its own budget-related decisions to an EU body based in Brussels.  This also renders the notion of a fiscal union chimerical.

His solution, though, is to go back to the Maastricht treaty roots, terminate bailout efforts—and not just for Greece—and require individual member nations to see to their own fiscal houses, without welfare payments from their fellow member nations.

The advantages which he lays out for this return are these:

…going back to the original state of things also means returning to an environment controlled by market forces.

The hard truth is that the voters in each country make the final decision about whether to honor or violate treaty obligations, so they also bear the responsibility for dealing with the consequences of their own decisions.

But then he says:

Those incapable or unwilling to [toe the economic line] need to get out—of their own accord rather than by getting the boot.

But such a solution does not address the fundamental reason for the failure of the euro zone—that utter lack of a consistent world view on the part of the constituent nations.  Given the broad differences the nations have concerning, for instance, the purpose of money, such consistency is impossible—nor should one be imposed from on high.  Aside from the immorality of the imposition, and its attack on individual liberty, the imposition would be illogical.  If the member nations are to be left to their own devices in getting out of their troubles, they must be left to their own considerations of what is important to them.  Yet these differences make it impossible for every nation to toe the euro zone’s—much less the Maastricht and Lisbon Treaties’—economic line.

My take is that Greece should depart the euro zone.  Europe, as a whole, does not need a common currency.  Instead, Europe should be decomposed into separate and distinct common currency zones, each of which must consist of a far more homogeneous membership, in terms of societal imperatives and political and economic philosophies.  This greater commonality of purpose will make each individual currency zone far stronger than is the present entire euro zone, and were these currency zones to form a free trade zone the members would be yet stronger.  As for Greece, it easily could become an effective and valued member of one of these smaller, more homogeneous groups.