While little has been confirmed by Berlin police, the likelihood of an accident appears remote and the similarity to the Nice attack is glaring. Trucks look to be a new weapon of choice and we can expect to see more of them used.

The selection of the target, one of Germany's beloved Christmas markets, where families gather to eat traditional foods into the night, seems calculated to rend as violently as possible the country's new social reality from its comfortable traditions.

Germany's reality is that it is the pillar of Europe at a time when the continent's unity is being frayed, in large part, by fierce debates about immigration, and which faces its own anxiety about the recent influx of asylum seekers.

The country's older Muslim communities, while not without their problems, are not beset by the same entrenched disaffection and isolation that fuel violent extremism in France and Belgium.

But the initial warmth and pride that accompanied Chancellor Angela Merkel's extraordinary gesture of granting entry to about 1 million asylum-seekers during 2015 has faded.

If the Breitscheidplatz attack turns out to be an act of terrorism and if, as some German media were reporting on Tuesday, the driver was a recent asylum seeker, it would intensify the debate about immigration and strengthen far-right parties, according to Benjamin Schreer, the German-born head of Macquarie University's department of security studies and criminology.

In particular, the populist, anti-Muslim and Eurosceptic "Alternative for Germany" party, which has already done well in local elections, could gain seats in the federal Parliament at Merkel's expense in next year's poll.

But he pointed out that Germany's political system is structurally more resistant to extremes and the far right remains anathema to most Germans.

"They could get a good result but not on the same scale as other European countries," Professor Schreer said. "The pressure is going to intensify and the government has to be seen to be running a tougher line. But it would be wrong to say Germany's moving in the same direction as France with [far-right leader Marine] Le Pen."

Stephan Fruehling, a German-born security expert at the Australian National University, said the mass sexual assaults in Cologne last New Year's Eve – attributed largely to men of Arab and north African descent – had spurred such a strong backlash against the mass intake of asylum seekers that politics had been set on a path that was unlikely to change much after Breitscheidplatz.

Both experts said that while there may be more money for security and tougher laws to remove failed asylum seekers, the idea of major upheaval in the nation that lies at the heart of Europe is far-fetched, even if Merkel is weakened or removed.

"It's not just Merkel who is deeply tied to European integration," said Professor Schreer. "That has been ... an integral part of mainstream German politics and mainstream society. I see a majority of Germans wanting Germany to play that role and ... certainly not become Britain in terms of that Eurosceptic outlook."