American activists en route to join the latest flotilla challenging Israel's siege of Gaza found themselves in an unforeseen but familiar situation last week.
In a big city's main square, angry young people were assembled en masse, spurred to action by a crisis in their economy and in their faith in their government.
But this Tahrir Square-style mobilisation of a generation was unfolding not in Egypt but in Syntagma Square in Athens, where the flotilla activists had assembled to prepare for their boat journey.
The graffiti on walls around the square matched the one word which reverberated through the crowd: "Oxi!", Greek for "No!". (This is a potent slogan, because Greeks know that Oxi! was the watchword of resistance to Italian and German occupation during World War II. )
The flotilla activists, who had come together to begin a voyage of support of Palestinians under siege, instead found themselves on the front line of Europe's new anti-austerity intifada.
Greece's parliament votes today on the latest austerity package demanded by the European Union as the price for further bailout loans to avoid a default on the Greek national debt.
Yesterday hundreds of thousands of Greeks launched a 48-hour general strike, the second walkout this month, aimed at expressing popular resistance to the proposed measures.
Greece is already bankrupt - its debt is around 150 per cent of its stagnant GDP, and it staves off default on that debt only by taking on more debt, at EU insistence.
But the price of further borrowing includes a range of austerity measures almost certain to plunge the Greek economy further into decline, shrink GDP and consign hundreds of thousands more of the 10.7 million Greeks to long-term unemployment and poverty.
Similar fates may await Spain and Portugal, and there, too, young people are already on the streets. They may yet be joined by their peers in France and Britain, amid austerity programmes in those countries.
While German politicians play to their voters with complaints about hardworking Teutons having to bail out profligate Mediterranean slackers, young people in the affected countries know that the core purpose of the bailouts by euro-heavyweights is, in fact, to save French and German banks. And they know that those same banks had encouraged Greece's profligate borrowing, and so would be most exposed in any Greek default.
The hundreds of thousands of Greeks who believe that the bailout terms mean an impoverished future simply don't buy the rationale for rescuing the banks at that price.
And that explains the uprising.
To be sure, this thinking may seem quixotic to those reared on the IMF consensus of shaping government policies according to the rules of capital markets. But the millions of young Europeans beginning to think about rebellion are not impressed by the rules of an economic system that offers them so little hope of even matching their parents' lifestyle.
Indeed, Greece is simply the flashpoint of a protest wave sweeping southern Europe's more cash-strapped economies - Spain and Portugal in particular. This wave is likely to spread, since young Europeans are in constant communication through new technologies.
These young adults are finding that the postindustrial capitalist economy, dominated by transnational finance, lacks the internal dynamism to provide them with jobs and economic security. Comparisons with the Arab Spring are inevitable.
A number of different factors (not all of them present in Europe) combined to ignite the Arab rebellion, of which the central theme is the inability of the status quo to meet the aspirations of youth.
Youth unemployment is above 25 per cent in the Arab world, and 100 million more young people will enter the job market over the coming decade. A social explosion, analysts said, was all but inevitable.
But European policymakers, who looked on benevolently as the Arab Spring rolled on, seem oblivious to, or impotent to prevent, the impact of the financial crisis on their own young generation.
Youth unemployment in Spain stands at 40 per cent, in Greece at above 35 per cent, and in Portugal at 27 per cent. In Britain and France the figure stands at around 20 per cent.
Small wonder then that millions of young Europeans have begun taking to the streets, suddenly aware that when the system is in crisis their governments tend to put the interests of credit markets first.
Whether the issue is jobs or cuts in education and social services, young Europeans - like their Arab peers - believe that the rules by which their economies are managed no longer offer them a path to economic security, much less prosperity.
The centrist government in Greece is playing by the rules of the credit markets in order to keep the country solvent. But citizens are increasingly willing to challenge the banker-friendly post-Cold War Western economic consensus.
The bailouts aimed at preventing defaults in Spain and Greece offer young people very little hope for change. Governments say the iron laws of global finance leave them no alternative to austerity measures that will shackle and shrink their economies. But well-educated yet jobless young people are unwilling to view the orthodoxies of global credit markets as immutable natural laws.
Of course the democratic states of Europe are very different from the mukhabarat autocracies targeted by the Arab rebellion. And Europe's basic standard of living is far higher than that of the Arab world.
But both systems have this in common: they have run up against their failure to offer their young people a path to realise their aspirations.
Tony Karon is an analyst based in New York. Follow him on Twitter @TonyKaron