@Lustig Andrei,
I don't know enough about domestic politics in Germany to comment on much of the above.
However, with respect to Greece, I suspect the issue has more to do with the willingness of the Greek people, through their political process, to face, all at once, the consequences of the past profligacy of their governments and those who benefitted from its excessive spending and financial deceptions. If Greece is to stay in the EUROZONE then the donor nations will want assurances that the price to them is clear, bounded and acceptable, and that the Greeks will, without delay, institute and stick to the financial reforms and spending restraints required to make it work at that price.
The advantage of leaving the EUROZONE and reinstituting the Drachma is that the ordinary market process will devalue the new Greek currency to whatever level required to match their government spending restraint (or lack of it) and renewed economic productivity (or lack of it). The Greeks won't have to face the music all at once - things will just happen to them, and the wealth of all the savers among them will be wiped out. Given their past dependence on government and recent unwillingness to face the music, I strongly suspect that their departure from the EUROZONE is inevitable.
All the talk about austerity seems strange to me. The observable fact is that no one wants to lend the Greek government the money they need to continue their spending. The transition happened suddenly about 18 months ago with Greek debt at about 125% of GDP; Greek current deficits soaring; and the history of past financial deceptions by the Greek government becoming known. Not long ago intrest rates on Itallian government bonds began soaring at a point where Italian debt was about 120% of GDP and Italian current deficits were chronic and high. A similar thing happened to Spain where national debt was much lower (about 60% og GDP I believe) but current deficits very high. A Greek-like crisis appeared imminent. Both countries have very high unemployment, particularly among the young, and highly reulated, rigid labor markets that inhibit new business startups and measures to raise economic productivity. I suspect these were factors as well. It was the creation of an EU rescue fund that thwarted a collapse then.
Somehow all these countries need to restore the confidence of those who would lend them the money they need to continue government spending. Increased government borrowing and spending does not seem to be a feasible way to do that, no matter what that little weasel Krugman may say. They need to stimulate new private sector economic activity; raise the labor productivity of their workforce and, try to increase their export earnings. All that appears to require, more private sector investment, faster enterprise formation, increased labor market flexibility, lower wages and higher productivity.
I don't think there is any economic theory that can reliably tell us when such loss in confidence among potential lenders will occur with governemtns running large current deficits. All we know is that the crisis happens fairly suddenly and without much warning. Overall debt levels as a function of GDP are a factor, as are other issues likecureent deficit trends, the rates of capital formation and new business enterprise formation, labor productivity and the flexibility of financial and labor markets to deal with the required changes - in short all the factors that might encourage potential lenders that the debts will in fact be repaid.
If a nation needs to borrow money on a continuing basis then it must sustain the credibility its potential lenders need to make their bets on it. Often that calls for changes that the former protected classes of citizens who benefited from the former restricted labor or financial markets or directly from government spending will call "austerity". I suspect the potential lenders and bond buyers would call it something else - like financial integrity, economic productivity, adaptability and the apility to produce values goods and services at a competitive price.
