Chancellor Angela Merkel on Saturday urged Europe to defend democracy and freedom as Germany marked 30 years since the fall of the Berlin Wall, warning that such gains must not be taken for granted.
At a solemn ceremony in a church standing on the former "death strip" that divided East and West, Merkel said the Berlin Wall reminds "us that we have to do our part for freedom and democracy".
"The values upon which Europe is founded... they are anything but self-evident. And they must always be lived out and defended anew," she told guests from across the continent.
On November 9, 1989, East German border guards, overwhelmed by large crowds, threw open the gates to West Berlin, allowing free passage for the first time since the Berlin Wall was built.
The momentous event would end up bringing the communist regime crashing down, and led to German reunification a year later.
But the euphoria for liberal democracy that characterised the epochal event then has somewhat dissipated three decades on, as the Western alliance that helped secure those achievements is riddled with divisions.
Cracks have appeared within the European Union as former eastern bloc countries like Hungary or Poland are accused by Brussels of challenging the rule of law.
Domestically, Germany is also struggling with a resurgent far-right, which has gained a strong foothold in its former communist states by championing a nationalist and anti-immigration message.
Merkel said the past must serve as a lesson, noting that the collapse of the Berlin Wall is "history and teaches us that no wall that keeps people out and limits freedom is so high or so wide that it cannot be broken through.
"That applies to us all in East and West: we stand stripped of any excuses and are required to do our part for freedom and democracy."
- 'Fiercer debate' -
Under grey skies, President Frank-Walter Steinmeier and his counterparts from Poland, Hungary, Czech Republic and Slovakia put roses through cracks in part of the Wall that still stands at Bernauer Strasse, in the north of central Berlin.
Meanwhile across the German capital at the west Berlin ground of German first division side Hertha, a replica of the Berlin Wall was erected on midfield Saturday, only to be knocked down just before the match kicked off between the home side and east German club Leipzig.
Steinmeier however noted the graver atmosphere at this juncture compared to other celebrations marking the key event in the German calendar five or 10 years back.
"In Germany, we are debating and yes, fighting, more than before, about German reunification and its consequences," he told his central European guests at lunch.
"In Europe too, in your countries and also between the European societies, there is a more intensive and fiercer struggle not only on the future of Europe but also on the interpretation of the past."
Differences are not only resurfacing between the former east or west blocs.
Two days before the anniversary of the epochal change, France's President Emmanuel Macron charged that transatlantic partnership NATO was suffering from "brain death".
Merkel responded with uncharacteristic sharpness, calling such "sweeping judgements" unnecessary.
The ensuing storm over NATO laid bare the growing tensions between traditional allies, as Donald Trump's America First policy, Britain's Brexit struggles and differences on how to handle a resurgent Russia put a strain on ties.
- 'Rising authoritarianism' -
The bad-tempered prelude to the festivities stood in sharp contrast to celebrations five years ago, when former Soviet leader Mikhail Gorbachev and ex-Polish president and freedom icon Lech Walesa were present.
This time, US Secretary of State Mike Pompeo's visit ended Friday, while Macron is only planning a flying visit on Sunday.
In a tweet on Saturday, Macron also urged Europeans to uphold the hopes for freedom that drove East Germans in 1989 to bring the Wall down.
"Let us be just as courageous and live up to their expectations."
Pompeo meanwhile left behind a stark warning: "As we celebrate, we must also recognise that freedom is never guaranteed."