These are unprecedented times in Europe. For the second time this year, a European country has made an official diplomatic protest against another member of the EU club. This week Greece recalled its ambassador from Austria because of a massive row over refugees. When European ambassadors were recalled in the past, it was usually from dictatorial countries or because of a major security crisis. This time, it’s happening among fellow European democracies.

Nor was the language used very reassuring. Greece accused Austria of “attitudes that have their roots in the 19th century” – a reference to imperial power plays. And this came just weeks after the Polish foreign ministry summoned the German ambassador in Warsaw, to complain about “anti-Polish” statements made by German politicians.

So here we are, watching how a Pandora’s box of national grievances, often going far back in time, is being reopened in Europe. Scratch the surface of the EU’s shared sovereignty and cooperation, and it is amazing how quickly old antagonisms can resurface. What does this all mean?

History and national passions still loom heavily just about everywhere. The Balkans, at the heart of the migrant crisis these days, risk reopening barely healed wounds. New border controls are being imposed and troops have been deployed (to control migrants between Croatia and Slovenia).

Austria has suddenly shown a new assertiveness in the region, striving to take a leading role in stemming the flow of refugees. That has reawakened memories. It didn’t take long for some Balkan commentators to wonder about lingering nostalgia for the Habsburg era, when the Austro-Hungarians ruled from Dalmatia to Transylvania.

Germany’s past has been brought up also, as critics in eastern Europe hit out against its refugee policies. Chancellor Angela Merkel has been accused of trying to strong-arm neighbours into following its “moral imperialism” (in the words of Hungary’s Victor Orbán).

There have been moments when rhetoric has flirted with hysteria. Remember how, last year, in the midst of the Greek bailout crisis, some Athens media depicted Merkel in a Nazi uniform. One poster showed a photo of her finance minister, Wolfgang Schauble, with the words: “He drinks your blood.” And look no further than Calais: on each side of the Channel there has been talk of ancient rivalries going all the way back to Agincourt – all this while refugees struggle on, from one camp to the next.

The pessimist take on the EU is that this project will soon drop into the dustbin of history – an idealistic but flawed endeavour, disintegrating before our eyes because of its failings.

But take another glance, and events point to the opposite: as tensions pile up, the EU has arguably never been more necessary. It is an indispensable framework to overcome irrational behaviour. Simply put, it offers the only decent way out of these messy disputes that – as we are all now rediscovering – refuse to die. The EU is the best thing we have to prevent us from treating each other as enemies. That can hardly be swept away with a shrug.

One clear lesson is that the EU certainly has not abolished the nation-state – nor was it actually ever meant to. That’s important because the nation-state is the central reference point that most Europeans relate to when they think of their identity. The “European demos”, the notion that we might all merge into a single collective form of citizenship, simply never took root. There is no European passport to speak of – our documents may say “European Union” but the main mention is our nationality.

Those who raise the spectrum of a “super-state” crushing national sensitivities, or of a “rigid straitjacket imposing uniformity on countries”, conveniently forget this. The “ever closer union” always referred to the “peoples” of Europe, it never meant that states would actually dissolve. Those who still worry about the dangers of a federalist vision can rest easy, for it has long faded.

The EU, whatever its flaws, still offers our best way out of disagreements through dialogue. It is based on the idea that we can, and must, search for consensus and pitch together, instead of hunkering down in the frailty of our limited, separate, national silos. It is often tedious, full of aggravation and long, painstaking nights around negotiating tables – but, in the end, it is better than the alternatives.

Nor is Europe about deciding who is right and who is wrong. Greece is angry because it thinks Austria has been plotting with regional allies – to trap hundreds of thousands of asylum seekers on Greek territory by cutting off migration routes to the north. The reason Poland’s government lashed out at Germany last month was because it suspected Berlin of leading a charge against its democratic backsliding.

Yet when things turn sour, responsibilities are in fact often shared. Austria was clumsy when it chose an ad hoc Balkan format for its Vienna summit on refugees this week, which excluded Greece. Athens has legitimate reasons to worry about unilateral decisions being taken by its northern neighbours on asylum quotas and border controls. But that doesn’t erase the fact that Greece has, until recently, been mostly content to wave large numbers of refugee families through on their journey northwards, without taking the trouble to register or screen them.

As for Germany, it is undeniable that Merkel has been the only European leader to hold fast to the continent’s humanitarian obligations towards refugees. But it is just as true that she made a mistake when she unilaterally, without consultation, launched her open-arms policy last September.

This is what happens when Europeans start giving up on working towards consensus: what you get is chaos, and nobody gets closer to finding solutions. Nationalist passions are aroused – of the type many thought long forgotten. The European project was built to counter such dangerous situations.

Now, 70 years of political cooperation and of hard, collective work aimed at dispelling the ghosts of the past are being threatened. No wonder representatives of the six founding European community states recently felt the need to meet and highlight their original philosophy. It’s time to get back to basics.