It should have been a normal family chat in late midsummer in Berlin. Kerstin Falkner, 22, and her new partner, Andreas, eight years her elder, were sitting in the back of Metzer Eck, the corner bar run by her mother, Bärbel, discussing where they might go for their holidays.

Only one thing was out of key: instead of joining in, Bärbel was sitting in the corner next to me, trying to keep back her tears. She simultaneously feared and hoped for the same thing: that they might not be coming home.

It was the summer of malcontents on the wrong side of the Berlin Wall. The first half of 1989 had been marked by change to communist regimes in eastern Europe. In Poland, after a decade of rebellion quashed by martial law, the government and the free trade union Solidarity had forged an agreement to differ, and then to agree. There had been a partly free election in June, after which Solidarity members entered parliament. In Hungary “goulash communism”, de facto toleration of private enterprise – which made for a more liberal and affluent economy than its communist neighbours – was rapidly leading to a similar attitude in politics.

The exception was East Germany, where change was unthinkable. It was an old joke that the former Soviet occupation zone, despite its new name, was neither German, nor democratic, nor a republic. In reality it was clearly not democratic, but it was arguably a republic. And definitely German. Its leader, Erich Honecker, far from being an east German, came from the most westerly part of prewar Germany, the Saarland, heavily industrial and dominated by the Communist party to which he belonged. Arrested by the Gestapo, he had spent 10 years in a Berlin prison, breaking free only as the Red Army entered the city.

Honecker had been instrumental in building the “antifascist protection wall”, which he boasted could last 100 years. When I first moved to East Berlin to work for Reuters in 1981, I picked up a 20th anniversary poster with a Honecker lookalike, sporting his trademark heavy-framed glasses, among “heroic” army construction workers.

East Germany’s leader was a true believer. The new thinking in Moscow, with Mikhail Gorbachev turning a blind eye to events in Poland and Hungary, and visiting West Germany to rapturous reception, made Honecker all the more determined to enforce rigid communism and put down any protest.

Facebook Twitter Pinterest East German border guards demolishing a section of the Berlin Wall, 11 November 1989. Photograph: Gerard Malie/AFP/Getty Images

Honecker felt still further threatened when Gorbachev, asked discreetly by West German media about the possibility of eventual unification, said obliquely: “Time alone will bring change.” Nobody envisaged how little time it would take.

The rest of the world was still looking to the past. That April I had joined hordes of journalists in the little Austrian border town of Braunau am Inn, expecting to see far-right gangs turn up at the house where Adolf Hitler was born, to commemorate his 100th birthday. In the event, there were more of us than them.

In May 1989 I visited Otto Habsburg, heir to the abolished Austro-Hungarian monarchy, in his home outside Munich. A fervent promoter of European unity, he planned to encourage a “picnic” on the border between Austria and Hungary, a token of East-West reconciliation, during which the closed frontier would be thrown open for several hours, a portent of the changing politics. That day, 19 August, showed how fast it was changing. East Germans like Kerstin and Andreas, if they could go abroad on holiday at all, were limited to other Soviet satellite countries, and needed a visa for those. The most popular was Hungary, with its gentle climate and the warm, shallow Lake Balaton. But that summer, with the GDR increasingly feeling like a prison camp, many of the thousands that came were not going home, in such numbers that the Hungarians couldn’t fulfil their agreement to forcibly repatriate them.

As soon as the token stretch of border opened, hundreds of East German “holidaymakers” turned up out of nowhere to pile through into Austria. An overnight phenomenon was created. The border was closed again, but with fortifications gradually being dismantled, local people gave them advice on where best to sneak through.

The East Germans kept coming, and Budapest would not now send them back. It announced all borders to the west would be opened within a month. Hungary had become East Germany’s unlocked back door. But East Berlin moved fast to have the front door slammed: Hungary’s northern border to Czechoslovakia closed. Unable to get farther, the crowds now simply piled into the West Germany embassy in Prague, soon to become massively overcrowded.

Back in Berlin, Kerstin and Andreas had planned to go to Hungary, but assumed that border too would soon be closed. So they decided on the “safe” option: Poland, for which they had visas, and a friend to stay with. Surely, they thought, if a deal was done in Prague, the same would eventually be done in Warsaw? They got out the other map.

Facebook Twitter Pinterest East Germans celebrating while crossing from Hungary into Austria. Photograph: Chris Niedenthal/The LIFE Images Collection via Getty Images

A few days later, Karin Beutler, a friend of mine, grabbed me on the street to announce ecstatically, “Ich bin los, Peter!” (“I’m out of here!”) A talented would-be artist, Karin had been forced to work as a mechanic. Her brother Siggy had spent six years in Bautzen top-security prison for attempting Republikflucht (“flight from the republic”) before being expelled to the west. Honecker’s policy was to punish failed escapees then ironically grant them what they wanted, if only to be rid of “antisocial nuisances”. Karin had taken the alternative option: to apply officially for permission to leave. With clouds of unrest on the domestic front gathering, the regime was getting rid of as many potential troublemakers as possible. Her request had been granted: in two weeks she would be able to cross the wall to join Siggy in West Berlin.

Little did any of us know that in six weeks the wall itself would be gone. The day after my meeting with Karin, Günther, a friend of mine from Leipzig, (he had introduced me years before to the Auersbachkeller, the 15th-century beer cellar described in Goethe’s Faust) rang to say that the regular peace gathering he attended in the city’s historic Nikolaikirche, where he was a flautist, had taken on a political angle. More than that, the several hundred who regularly met there had grown to more than a thousand and were now demanding greater political freedom along the lines of what had happened in Poland and Hungary, and also that the right to travel be restored and expanded. To make their point they had decided to do the unthinkable: march on the streets the way West German students did in protest against American missile deployment. He was going to join them. Did I want to come along? I did.

The following Monday, after a beer in the Auersbach we joined several thousand marching from the Nikolaikirche around Leipzig’s inner ring road, carrying makeshift banners under the slogan “Wir sind das Volk” (“We are the people”). I still have one: black paint daubed on a scrap of red cloth.

The wheel had begun to roll. Over the coming weeks and months the Leipzig parades became a weekly ritual growing to tens of thousands. Protesters still lived in fear that the Soviet army might intervene, as in Budapest in 1956, and Prague in 1968. It didn’t. Gorbachev wouldn’t grant Honecker’s wishes.

I look back on those heady days with my own personal nostalgia for a revolution I felt part of. Kerstin and Andreas finally got out via Warsaw, along with hundreds of others in a sealed train. I smuggled their papers into West Berlin. Three weeks later, on 9 November, the wall fell.

Within a year Germany was united and Europe transformed, the cold war ended. The people of eastern Europe regained freedom and saw the European Economic Community, forebear of the EU, as their guarantor.

But a guarantee needs rules if it is not to become populism. The Germans know this too well. Claiming “popular democracy”, Hitler had used rhetoric and twisted statistics in referendums at every stage of his rise to dictator.

He first pulled Germany out of the League of Nations, reclaimed the Saarland (“protect our borders”), remilitarised the Rhineland (“boost our defences”), took over the presidency as well as the chancellorship in the new role of “leader”, and then gave himself supreme power, annexing Austria and banning other parties, all without ever winning a parliamentary majority. No surprise that referendums at national level are illegal in modern Germany. Mistakes need to be made before they are learned from.

Peter Millar worked in eastern Europe from the 1980s onwards for Reuters, the Sunday Telegraph and the Sunday Times. He was the BBC’s What the Papers Say foreign correspondent of the year in 1989 for his reporting on the end of the cold war and is the author of 1989: The Berlin Wall: My part in its downfall (Arcadia Books)

Year of change

6 February 1989

Solidarity and the Polish Communist government begin talks.

2 May

Hungary begins plan to remove “Iron Curtain” fortifications along border with Austria.

4 June

Solidarity victorious in a partially free election in Poland.

7 July

Mikhail Gorbachev tells Warsaw Pact leaders they are free to set their own path to socialism and says he can envisage “a change in the social and political order in some countries”.

19 August

Six hundred East Germans attend “Pan-European picnic” in Sopron on the Hungarian-Austrian border and cross over to Austria and West Germany.

10 September

Hungary officially opens border with Austria, allowing thousands of East Germans to flee.

7 October

Gorbachev visits East Germany to celebrate 40 years since its founding and urges Erich Honecker to pursue reforms.

18 October

Honecker resigns and is replaced by Egon Krenz.

9 November

Demolition of Berlin Wall begins.