On Thursday, it was Italy's turn for a day of anger. Rival Marxist factions in Rome began by fighting each other rather than the common enemy, as anyone familiar with leftwing protest could have predicted. Tiring of internecine warfare, the demonstrators then threw eggs at the Italian Senate and denounced Goldman Sachs, which, as well as being the world's most dangerous investment bank, was also once the employer ofMario Monti, who now happens to be Italy's unelected prime minister.
In Palermo, Milan and Turin, the police had to protect financial institutions, while demonstrators chanted: "Save schools, not banks." For all the familiarity of their concerns, the protesters missed a glaring point. Not as glaring as the point the Occupy London movement missed when it set out to close the City and force the vultures of Goldman Sachs to resign and then decided to close St Paul's and force its clergy to resign. But a target that outsiders still find so large it overshadows all others.
The demonstrators did not attack the euro and denounce the men who had fitted it over Europe like a warder fitting a straitjacket over a prisoner. It never occurred to them that 100 years from now financial historians may be writing grimly comic accounts of how "moderate" bureaucrats and politicians of the utmost respectability fell for the utopian folly of creating a single currency, and assumed it could work without a single government that might act as a lender of last resort and redistribute wealth from its rich to poor regions.
Nor is it occurring to the mainstream European left. Officials working for the European Parliament's Progressive Alliance of Socialist and Democrats told me that no one talked about breaking up the euro. They did not mean that not one of the parties the alliance represented had decided to advocate the break up or the abolition of the euro as official policy. They meant that not one of the 184 social democratic members of the European parliament from 27 countries had suggested such a blasphemous idea in public or in private. It was unthinkable. Taboo.
I don't wish to dismiss European social democracy. Leftwing European politicians have many essential reforms to offer. Social democrats deplore the way that Sarkozy, Merkel and the European Commissionhave shifted the burden of a bank-created crisis on to "the shoulders of wage-earners, taxpayers and public services". They understand that Merkel's plans for a European-wide regime of "fiscal responsibility" will be achieved by slashing back on welfare states and collective bargaining rights. Without any compensating plans to boost growth, they guess, rightly, that stagnation and penury will follow. They want attacks on tax havens, mandatory public investment, ferocious controls on the banks and green energy – a programme, in short, that would suit Britain as well as it would suit the rest of Europe.
For all their virtues, however, they cannot see the fundamental flaw in the notion of locking Greece, Italy, Spain, Portugal, Ireland and – who knows? – even France into a single currency with Germany and denying them the ability to compete by removing the option of devaluation.
The euro is off-limits for the European left. Its assumption that the project remains benign is of enormous help to the European leaders it opposes. As long as criticisms are confined to the right and communist parties that have not got over the fall of the Berlin Wall, the European establishment can say that their only real enemies are the nationalists and totalitarians Europe could do without.
Even the British, who did not experience communism or fascism, ought to have sympathy with those who yearn to make the eurozone work despite all that has happened. For the original six members, European unity offered an escape from Nazism. For Spain, Greece and Portugal, it was an escape from militaristic rightwing dictators. For the nations of the old Soviet empire, it was an escape from communism. Dimitris Hadzisokratis, who led the occupation of Athens polytechnic in 1973, a heroic moment of resistance that began the overthrow of Greece's military junta, is now the leader of the Greek Democratic Left party.
Despite, or maybe because of, the crisis in his country, he told me that the answer to the eurozone's troubles must be more federalism, not less. For him and his generation, the European Union offered an escape from dictatorship to a better world of human rights, the rule of law and personal freedom.
I suspect that one day they will say that the EU's unforgivable crime was to take their idealism and hope and throw them away for the sake of a harebrained currency experiment. But they are not saying that now. They have too much invested to give up on the euro.
How long their resolution will last is open to doubt. In Italy and Greece, the EU offered semi-honest government that compared well when set against the corruption of the local elites. A citizen of Rome disgusted by the behaviour of Silvio Berlusconi could look on distant Brussels as a countervailing force. Now, Brussels is no longer a kindly relative who can be called on for help when the wilder members of family go off the rails. It isn't distant, but in Italians' faces and in power in Rome. The foundation of the unelected Monti government is an ominous moment in European history. Neither Monti nor any of his colleagues has condescended to do anything so vulgar as stand for election. Herman van Rompuy, the president of the European Council, and another stranger to democratic legitimacy, revels in the absence of popular sovereignty. Unelected power was necessary to whip Italy into shape, he told Italians. Their "country needs reforms, not elections".
If the reforms fail to deliver growth, and the eurozone as presently constituted almost guarantees that Italy, Greece, Spain and Portugal will fail, the EU will have no one to hide behind. Italy's failure will be its failure and its responsibility. British Euro-sceptics should not rejoice. Europe is crawling with ultra-nationalists, le Pen-ists, Northern Leaguers, crypto-fascists, anarchist nihilists and unreconstructed Marxist-Leninists who will rejoice with far more enthusiasm.
The historic mission of the democratic left has been to fight all of the above and beat all of the above. Whether they will be able to do so while defending a currency zone that is falling apart before the voters' eyes is a question they need to find an answer to fast.