It began in Athens. It is spreading to Lisbon and Madrid. But it would be a grave mistake to assume that the sovereign debt crisis that is unfolding will remain confined to the weaker eurozone economies. For this is more than just a Mediterranean problem with a farmyard acronym. It is a fiscal crisis of the western world. Its ramifications are far more profound than most investors currently appreciate.

There is of course a distinctive feature to the eurozone crisis. Because of the way the European Monetary Union was designed, there is in fact no mechanism for a bail-out of the Greek government by the European Union, other member states or the European Central Bank (articles 123 and 125 of the Lisbon treaty). True, Article 122 may be invoked by the European Council to assist a member state that is “seriously threatened with severe difficulties caused by natural disasters or exceptional occurrences beyond its control”, but at this point nobody wants to pretend that Greece's yawning deficit was an act of God. Nor is there a way for Greece to devalue its currency, as it would have done in the pre-EMU days of the drachma. There is not even a mechanism for Greece to leave the eurozone.

That leaves just three possibilities: one of the most excruciating fiscal squeezes in modern European history – reducing the deficit from 13 per cent to 3 per cent of gross domestic product within just three years; outright default on all or part of the Greek government's debt; or (most likely, as signalled by German officials yesterday) some kind of bail-out led by Berlin. Because none of these options is very appealing, and because any decision about Greece will have implications for Portugal, Spain and possibly others, it may take much horse- trading before one can be reached.