To an extent I see a certain folk memory of the Great Depression driving this unease. After the Wall St crash of 1929, a short term stability was restored, but over the next two years the original liquidity crisis, caused by so much stock being bought on margin, became a solvency crisis, as those wiped out in the crash gradually "restructured". In May 1931 the Austrian bank, Creditanstalt went bankrupt, and the crisis which had begun on Wall St. began to destroy the global banking system.
The current policy makers, led by Ben Bernanke, are close students of the history of the Great Depression. This is why they have been so aggressive in injecting liquidity and solvency where they think it is most needed.
The problem is that this has only moved the problem, not solved it.
Now governments will have to pick up the large bill for bank rescue, and the price of that is that they are being scrutinised more closely than ever. There is only so much demand for government bonds, and in the end governments too must live within their means, at least over the longer term. Whereas in the 1930s governments instituted a "beggar thy neighbour" policy: trade restrictions and high tariffs, now governments know that such protectionism does not work. The result is that they have to make cuts in their own expenditure: you might call it a "beggar thyself" policy.
In the end until the relative position between debt and the total size of the economy is controlled, then governments flirt with a meltdown in confidence. It is not so much what the governments actually do, but what they are expected to do, that is important. Thus both the UK and Germany are announcing dramatic cuts in expenditure. Given the fact that there have been some substantial revisions in the UK debt number which puts the country in a much better position, the cuts now announced may look a little swingeing. Nevertheless this is not about the detail: it is about trust and confidence. If the markets believe that the government can address the deficit in an orderly way, then they will retain their confidence in the system.
It is to the audience in the global markets that the coalition is addressing itself: and the rest of us will just have to be patient- and prudent.