TO MILLIONS the Berlin Wall—which as of today has been down for longer than it was up—was above all a symbol. It was a by-word for division and the post-war era in Europe. It played stage to an evolving caste of monumental historical figures: JFK, Willy Brandt, Walter Ulbricht, Ronald Reagan, Helmut Kohl. It gave way to German reunification and the birth of the euro.

But it was also the cause of countless private tragedies. It severed families. It destroyed opportunities. 173 East Germans were killed trying to cross it. One, 18-year-old Peter Fechter, was shot in 1962 while trying to scale the wall and left to bleed to death in the no-man’s-land, West German soldiers throwing him bandages in vain.

The story of this hateful barrier’s fall and the ensuing 28 years, two months and 27 days of German history is one of expanded individual horizons: it has meant previously unimaginable travel, enterprise, friendships and relationships (the proportion of German couples with one “Ossi” and one “Wessi” partner passed the 10% mark in around 2008). Among the touching reflections on the anniversary today have been social media posts to that effect by Germans speculating on how much poorer their lives would have been #ohneMauerfall (without the fall of the wall).

One experience is better documented than most. The wall’s construction in 1961 was Angela Merkel’s first political memory: “My father was preaching on that Sunday. The atmosphere was horrible in the church. I will never forget it. People cried. My mother cried too. We couldn’t fathom what had happened.” Just over 28 years later, working as a physicist in East Berlin, she was taking her regular Tuesday-evening sauna when travel restrictions were lifted. She later joined the crowds pouring across the border at the Bornholmer Straße bridge and, on the other side, wanted to call her aunt in Hamburg from a pay phone, but had no West German money. A woman who had dreamed of travelling to the West, perhaps to America with special permission on her retirement, would soon after plunge into the reunified republic’s politics and end up leading it. If she secures a fourth term as chancellor in the still-ongoing coalition talks she could end up having done so for over half of its post-wall history.

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Last week I sat down with John Kornblum, the former American ambassador to Germany and the brains behind Reagan’s “Mr Gorbachev, tear down this wall!” speech at the Brandenburg Gate in 1987. He theorises that the country’s modern history has moved in 20-30 year cycles. First there was the immediate post-war period from the late 1940s to the 1960s, marked by the sundering of the country and the ensuing dramas and culminating with the construction of the wall. Then came a period of greater stability and, from the start of the Brandt chancellorship in 1969, more national self-reflection in West Germany. Then with the fall of the wall came a third period: reunification and a process, centred on the red-green government of Gerhard Schröder from 1998 to 2005 but continued under Mrs Merkel, of Germany’s relaxation into normality.

The recoherence of Berlin over that later period is a testament to how far the country has come. Differences between the old east and west halves remain, some subtle (in the east street lights are yellow and the traffic-light man wears a hat, in the west they are white and he is bare-headed) and others more fundamental (Ossis support Union and are more likely to vote for the political extremes, Wessis cheer on Hertha Berlin and tend to vote centrist). But generally, to quote Brandt, “what belongs together grows together”. Central Berlin has been rebuilt, new east-west transport arteries like the cathedral-like Hauptbahnhof are open and others are under construction. Peter Schneider, a veteran chronicler of the city, writes: “The fall of the Wall and the reunification of Berlin’s two halves have sped up the city’s pulse, injecting new life energy. It’s as if the city had won back a temporal dimension that, during the years of the Wall, seemed to have disappeared from West Berlin and was merely alleged to exist in East Berlin: the future”.

To be sure, the past is visible too. Berlin epitomises the German knack for sensitively accommodating the scars of history. Parts of the wall have been preserved as memorials and much of the route is now traced by cobble stones which disappear under buildings built in the old death strip—The Economist’s premises in Berlin among them—and re-emerge on the other side. In a plot once bordered by the wall a block from the Reichstag, to which the Bundestag moved from Bonn in 1999, sits the Holocaust memorial, an undulating 5-acre sea of tombstone-like concrete slabs. When, last month, a local historian discovered a forgotten stretch of the wall in the woods by a suburban train line, it was a rare sight: an unarchived, uncurated piece of the city’s 20th century traumas.

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There is a nagging tension in the reunified city, between its oddball past and its grown up, worldly present. For decades West Berlin was an eccentric place, cut off by the wall and far away from mainland West Germany. Plenty left it for cities there, like Hamburg and Munich. To slow the flow, the authorities exempted its young men from national service, which helped attract those seeking alternative lifestyles to districts like Kreuzberg. The fall of the wall saw another influx, as artists swept into former eastern districts to benefit from the cheap accommodation. Today’s city—its centre the shiny capital of Europe’s largest economy, its inner suburbs mostly in the advanced stages of gentrification—is a far cry from the scruffy, charmingly mangled Berlin of the early 1990s.

Some fret that the city still has some growing up to do. They gripe about its administrative dysfunctions, its sometimes anarchic streets (illegal nighttime car races are the latest scare) and infrastructural embarrassments like the parodically problem-plagued new airport, now scheduled to open a decade late in 2021. “What kind of national capital is this?” goes the typical eye-rolling complaint. But more Berliners have a different worry: that its reinvention as a modern European political and start-up hub is driving out the working-class Berliners and poor bohemians who make the city the place it is. Local newspapers heave with tales from the battle lines: struggles between residents and property developers, vandalised yuppie flats and bars, squats stormed by police officers, cars torched in protest at one thing or another and conflicts between the city’s world-renowned night clubs and its zoning lawyers.

It all boils down to one basic question: can the unified Berlin be a misfit, free-thinking historical curiosity and a modern, globalised power centre at the same time?

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That quandary is a small part of a much larger one: if in Mr Kornblum’s scheme the post-wall Schröder-Merkel period of German adjustment to a new, reunified identity is drawing to a close, what does the next phase of its history bring?

It is awkward to remember, especially on a happy anniversary like this, but the wall was not just an atrocity, though it was that. It was also a stabiliser. Since unification in 1871 the “German question” has loomed: the country is too big for there to be an easy balance-of-power in Europe but too small to dominate the continent. This imbalance helped bring about the two world wars but, as Hans Kundnani argues in his book The Paradox of German Power, was temporarily suspended by Germany’s division from 1945. This subordinated the Prussian heartland to the Soviet bear and left behind a western, largely demilitarised, geographically marginal Germany comparable in size to Britain, France and Italy and capable of being bound into European institutions. The construction of the wall stabilised that solution to the German question; a moment, in the words of the historian Tony Judt, “when the great powers, whatever they said in public, heaved a private sigh of relief”. But later the wall fell, a reunited Germany was once more at the heart of Europe and the imbalance returned.

Its re-emergence may well define Germany's next phase and is already evident in several places. One is the growing east-west divide in the EU. Germany is economically and politically mighty enough to inspire resentment among its Visegrád neighbours, but not enough to influence their leaders, who like PiS in Poland and Fidesz in Hungary increasingly define their politics against that of Berlin. For all the (silly) talk about her being the “new leader of the free world”, Mrs Merkel could not even persuade her eastern neighbours to accept a relatively tiny number of refugees. Or take the euro zone, where Germany’s economic weight is creating imbalances (“suddenly Europe is speaking German”, gushed a leading Christian Democrat in 2011) requiring a level of further integration whose necessity its leaders remain slow to contemplate, notwithstanding tentative steps in the right direction in the recent coalition talks. Or consider the geopolitical picture, where Germany is big enough to make moves unsettling to its neighbours, like backing the Nord Stream 2 gas pipeline from Russia, but too timid to make proportional commitments to common security.

The management of these tensions probably means a redoubled alliance with France (where things look promising) and reconciliation with Poland (where they do not). The pre-wall period, then the wall period, then the post-wall period have marked Germany’s evolving post-war history. Now comes the post-post-wall period.