To put it yet another way, Germany is not ready - and may never be ready - to provide implicit insurance and underwriting for loans and investments made by Spanish banks, or Italian banks or French banks.

BBC: Eurozone banking union that works for Britain?

But if investors and creditors regard the proposals as credible, if banks are no longer considered too big to fail, the costs for banks of raising money would rise: as you will have deduced, the risks of investing in and lending to banks increases in proportion to the perceived reduction in the implicit insurance against failure they receive from the state.

BBC: The cost of making big banks safe

As it is, the government has an implicit role in terrorism insurance, when the chips are down.

ECONOMIST: Is a federal backstop for terrorist insurance necessary?