Could Germany afford Irish, Greek and Portuguese default?
The Western world remains where it has been for some time, delicately poised between anaemic recovery and a shock that could tip us back into economic contraction.
Perhaps the most conspicuous manifestation of the instability is that investors can't make up their minds whether the greater risk comes from surging inflation that stems largely from China's irrepressible growth or the deflationary impact of the unsustainable burden of debt on peripheral and not-so-peripheral eurozone (and other) economies.
And whence do investors flee when it all looks scary and uncertain, especially when there's a heightened probability of specie debasement - to gold, of course.
Unsurprisingly, with the German finance minister, Wolfgang Schauble, implying that a writedown of Greece's sovereign obligations is an option, and with consumer inflation in China hitting 5.4% in March, there has been a flight to the putative safety of precious metal: the gold price hit a new record of $1,480.50 per ounce for June delivery yesterday and could well break through $1,500 within days (say the analysts). Silver is hitting 30-year highs.
In a way, if a sovereign borrower were to turn €100bn of debts (for example) into an obligation to repay 70bn euros, that would be a form of inflation - it has the same economic impact, a degradation of value, for the lender. But it is a localised inflation; only the specific creditors suffer directly (though there may be all sorts of spillover damage for others).
And only this morning there was another blow to the perceived value of a chunk of euro-denominated sovereign obligations. Moody's has downgraded Irish government debt to one level above junk - which is the equivalent of a bookmaker lengthening the odds the on that country's ability to avoid controlled or uncontrolled default.
Some would say that the Irish government has made a start in writing down debt, with the disclosure by the Irish finance minister Michael Noonan yesterday that he would want to impose up to 6bn euros of losses on holders of so-called subordinated loans to Irish banks.
But I suppose the big story in the eurozone, following the decision by the European Central Bank to raise interest rates, is that the region's excessive government and bank debts are more likely to be cut down to manageable size by a restructuring - writedowns of the amount owed - than by generalised inflation that erodes the real value of the principal.
The decision of the ECB to raise rates has to be seen as a policy decision that - in a worst case - a sovereign default by an Ireland, or Greece or Portugal would be less harmful than endemic inflation.
But is that right? How much damage would be wreaked if Greece or Ireland or Portugal attempted to reduce the nominal amount they owe to levels they felt they could afford?
Let's push to one side the reputational and economic costs to those countries - which are quite big things to ignore, by the way - and simply look at the damage to external creditors from a debt write down.
And I am also going to ignore the difference between a planned, consensual reduction in sums owed - a restructuring that takes place with the blessing of the rest of the eurozone and the International Monetary Fund - and a unilateral declaration of de facto bankruptcy by a Greece, Ireland or Portugal (although the shock value of the latter could have much graver consequences for the health of the financial system).
So the first question is how much of the impaired debt is held by institutions and investors that could not afford to take the losses.
Now I hope it isn't naive to assume that pension funds, insurance companies, hedge funds and central banks that hold Greek, or Irish or Portuguese debt can cope with losses generated by a debt restructuring.
The reason for mild optimism in that sense is that those who finance investments made by pension funds and insurers - that's you and me by the way - can't get their money out quickly or easily. We simply have to grin and bear the losses to the value of our savings, when the stewards of our savings make lousy investment decisions.
As for hedge funds, when they make bad bets, they can suffer devastating withdrawals of finance by their investors, as and when the returns generated swing from positive to negative. But so long as those hedge funds haven't borrowed too much, so long as they are not too leveraged - and most aren't these days - the impact on the financial system shouldn't be significant.
Finally, if the European Central Bank - for example - ends up incurring big losses on its substantial holdings of Greek, Portuguese and Irish debt, it can always be recapitalised by solvent eurozone nations, notably by Germany and France.
However this is to ignore the node of fragility in the financial system, the faultline - which is the banking industry.
In the financial system's network of interconnecting assets and liabilities, it is the banks as a cluster that always have the potential to amplify the impact of debt writedowns, in a way that can wreak wider havoc.
That's built into their main function, as maturity transformers. Since banks' creditors can always demand their money back at whim, but banks can't retrieve their loans from their creditors (homeowners, businesses, governments), bank losses above the norm can be painful both for banks and for the rest of us.
Any event that undermines confidence in the safety of money lent to banks, will - in a best case - make it more difficult for a bank to borrow and lend, and will, in the worst case, tip the bank into insolvency.
Which, of course, is what we saw on a global systemic scale from the summer of 2007 to the end of 2008. That's when creditors to banks became increasingly anxious about potential losses faced by banks from a great range of loans and investments, starting with US sub-prime.
So what we need to know is whether the banking system could afford losses generated by Greek, Irish and Portuguese defaults.
And to assess this, we need to know how much overseas banks have lent to the governments of these countries and also - probably - to the banks of these countries, in that recent painful experience has told us that bank liabilities become sovereign liabilities, when the going gets tough.
According to the latest published analysis by the Bank for International Settlements (the central bankers'central bank), the total exposure of overseas banks to the governments and banks of Greece, Portugal and Ireland is "just" $362.2bn, or £224bn,
Now let's make the heroic guess that a rational writedown of this debt to a sustainable level would see a third of it written off - which would generate $121bn (£75bn) of losses for banks outside the countries concerned.
If those loans were spread relatively evenly between banks around the world, losses on that scale would be a headache, but nothing worse.
But this tainted cookie doesn't crumble quite like that. Just under a third of the relevant exposure to public sector and banks of the three debt-challenged states, some $118bn, sits on the balance sheets of German banks, according to the BIS.
For all the formidable strength of the German economy, the balance sheets of Germany's banks are by no means the strongest in the world. German banks would not be able to shrug off $39bn or £24bn of potential losses on Portuguese, Irish and Greek loans as a matter of little consequence.
This suggests that it is in the German national interest to help Portugal, Ireland and Greece avoid default.
If you are a Greek, Portuguese or Irish citizen this might bring on something of a wry smile - because you would probably be aware that the more punitive of the bailout terms imposed by the eurozone on these countries (or about to be imposed in Portugal's case) is the expression of a German desire to spank reckless borrowers.
But as I have mentioned here before, reckless lending can be the moral (or immoral) equivalent of reckless borrowing. And German banks were not models of Lutheran prudence in that regard.
If punitive bailout terms make it more likely that Ireland, Greece or Portugal will eventually default, you might wonder whether there has been an element of masochism in the German government's negotiating position.