On Sunday, Nov. 20, after Spain’s national-election votes were counted, the last major patch of red disappeared from the European map. For the first time in modern history every major capital in the continent, from Lisbon to Helsinki, is now home to a conservative government.

Spain’s national election has been fought at the peak of a monetary crisis that has already tossed Greek prime minister George Papandreou, Portuguese leader Jose Socrates and Irish prime minister Brian Cowen, all of them broadly on the centre-left, out of office.

The crisis has provoked a real-estate crash and soaring unemployment in Spain, where 25 per cent of the population and half of all youth are jobless, and last month forced long-reigning Socialist Party prime minister Jose Luis Rodriguez Zapatero to quit early after imposing deep and unpopular spending cuts with little success.

Voters replaced him with Mariano Rajoy, whose conservative Popular Party is promising far deeper cuts. Mr. Rajoy joined a near-unanimous bloc of rightists across the continent.

The blue-tide reversal has been extraordinary. A decade ago, in the midst of an economic boom, Europe was a near-solid wall of social-democratic red, with only Ireland, Spain and a handful of Eastern European states held by conservatives. Now the 27-nation European Union has only four smaller members – Cyprus, Slovenia, Austria and Denmark – that are governed from the left.

Never has such political unanimity governed Europe – ironically enough, at a moment when the disappearance of monetary and political unity appears crippling.

Still, not since the early 1990s, when a wide bloc of centre-right parties helped create the euro, has conservatism been the dominant European idea.

Indeed, this time Europe’s conservatives seem to be divided by a common ideology: Frictions between Germany’s Angela Merkel, France’s Nicolas Sarkozy and Britain’s David Cameron have all but paralyzed economic recovery. This has left some pining for the deep co-operation that existed a few years ago between leftists in Britain and Germany and conservatives in France and Spain.

More surprising, though, is that these disparate countries seem to change governing ideologies in tandem – after all, their elections are mostly fought on strictly national issues. In Spain’s vote, as with most European elections, continent-wide issues such as the euro-zone bailout do not figure at all.

“One of the surprising things that’s happened in the last 20 years or so is a Europe-wise synchronization of parties in power,” says Mark Franklin, a specialist on European elections and parties at the European University Institute in Florence. “It appears as if Europe is becoming a single polity, although we know voters don’t consciously think that way.”

When the European crisis began three years ago, there was an influential school of thought which held that it would produce a natural rush to the political left. After all, voters were furious at banks, finance capital and big corporations; not only that, but they were increasingly unemployed and dependent on government benefits. If the free-market economy had failed them, it seemed logical that they would turn to the parties of the big state.

And since it was mainly conservative parties that had created both the European Union and the euro currency, against the protest of many left-wing parties that still see European integration as a corporate profit-maximizing plot, you might have expected a backlash.

But it hasn’t worked out that way. While there have been huge protests against the centre-left governments of Greece and Spain from even further to the left, and successful “occupy” protests in several capitals, the voters have been overwhelmingly sending their protest votes rightward.

“If there is ever going to be a unified response to a unified situation, it would be the economic crisis … and you’d think that an economic crisis would be tailor-made for the left – but you’re not really seeing that, instead you’re seeing very different national responses,” says Paul Taggart, head of the politics and contemporary European studies department at the University of Sussex.

The blue tide is, in his analysis, more a simple matter of voters tossing out whoever happened to be in office when the crisis arrived – and in most cases, that was a centre-left party.

“The voter response that elects the British Conservatives is not the same as the voter response that elects the German Christian Democrats – the crisis plays out in different ways through different languages in different political systems,” he says.

But there does seem to be some connection between economy and ideology. An analysis this year by The Economist found that during the past two decades, periods of economic growth have tended to produce increases in the number of left-wing governments in power (with a two-year delay), and falling growth, as we’re seeing now, has raised the number of right-wing parties.

It isn’t quite a strong enough explanation to account for the entire continent’s politics. And, indeed, it may be possible that the left-wing parties drove themselves out of office by beating the right at its own game.

After all, these were not the tax-and-spend leftists of earlier decades. The big socialist and social-democratic governments of the 2000s were dominated by parties of fiscal restraint.

Mr. Zapatero is a perfect example: His Socialist government, elected by surprise in the wake of a 2004 Madrid terror attack that voters blamed on the conservatives, ran budget surpluses for most of his eight years in office, made important free-market reforms and oversaw large-scale growth of the private-sector export industry in Spain.

Likewise, Germany’s Gerhard Schroeder, whose Social Democrats provided the cornerstone of Europe’s red tide, was best known for slashing unemployment and welfare benefits and pensions that had become unaffordable under previous conservative governments. Britain’s Gordon Brown was famous for his fiscal restraint and low government debt.

In contrast, the new European conservatives have picked up a number of ideas from the left. At summits this month, Mr. Sarkozy and Ms. Merkel have been almost evangelical in their push for a Europe-wide micro-tax on financial transactions, sometimes known as a Tobin tax – a concept that a few years ago was supported only on the left.

(Mr. Cameron, who joins Canada’s Conservatives in opposing such a tax, attempted to strike a deal on Friday in which he would support a tighter economic and fiscal union among the 17 euro-zone countries in exchange for his continental colleagues dropping the transaction-tax idea).

And, in a final reversal of fate, it will likely be Europe’s true-blue conservative parties who, like it or not, will end up raising taxes, increasing government spending and building even bigger government – because they’ll have little choice if they want to resolve the crisis. In the process, they might reverse a decade of lower taxes and smaller government delivered by leftists.

By the end of next year, the blue wall will likely have some cracks. Mr. Berlusconi’s arch-conservative Italian coalition will likely (though not certainly) be replaced with a chaotic centre-left grouping. Mr. Sarkozy faces an election that may well see him ousted in favour of the Socialist Party, and Ms. Merkel’s German coalition is increasingly weak.

And, importantly, the conservative parties now in office will bear the brunt of the austerity and bailout programs, which will be unpopular with voters: Unless they can stay in office until the next wave of economic growth, they could be punished in the future for their currently popular policies. If the trends of the past 20 years are any guide, it could mark the beginning of a shift back to an all-red map.