PARIS — As Germany celebrates the 25th anniversary of the fall of the Berlin Wall on Sunday, we mark the passage of time. Historically speaking, time is a variable. Much can happen in a quarter century, or very little.

Twenty-five years was how long military service used to last for peasants in Tsarist Russia. In France, it's the number of years between the 1789 fall of the Bastille and the first return of the Bourbons in 1814. It's also the time between the beginning of the World War I in 1914 and the beginning of the World War II in 1939. But 25 years is also what separates 1815 from 1840. The rise of romanticism, of course, but also a chance for Europe to catch its breath after the shocks of the French Revolution and the First French Empire.

Historians often say that the 20th century started with World War I and ended with the fall of the Berlin Wall. Now, as Germany commemorates the fall of the Wall with noticeable discretion — in stark contrast with the 20th anniversary celebrations — how could we sum up the last quarter century?

We could quote Balzac and talk of "lost illusions." We could say that we have entered the "end of the end of history" to mock, in a cruel but justified way, the premature triumphalism of Francis Fukuyama. We could, like others, sadly define the past 25 years as an "interwar period" between the end of the Cold War and a new form of "fresh war" unfolding before our eyes in the Middle East, in Africa, Eastern Europe, and perhaps tomorrow in the China Sea.

The problem in this quest for denomination, and thus for meaning, lies in knowing whether to use as a starting point the beginning or the end of this period. France's Belle Époque (The Beautiful Era) was only later defined as the years that preceded World War I.

Should Ebola become the first great pandemic since the 1918 flu — which thankfully doesn't seem very likely — the past years would be defined as those that preceded the "great global health crisis."

In reality, and in a less apocalyptic way, if we had to keep two expressions to describe the last 25 years, I would rather speak of the "time of fragmentation," on the one hand, or highlight the "end of the American century," on the other. They are two ways to say the same thing, the second helping to explain the first.

Germany's rise amid global chaos

In hindsight, the best bits of news since the fall of the Berlin Wall don't come from the world's evolution. No, it kept breaking up further, from the USSR and the Balkans to, these days, the Middle East.

A wall in Cairo dedicated to 'martyrs of the Revolution.' Photo: Gigi Ibrahim

Amid global turmoil, borders have lost some of their intangibility. We used to resign ourselves to their artificiality to prevent their redrawing from translating into bloodshed. That is no longer the case. The convergence of empires on the decline and failed states explains most of this dangerous evolution. Everything is happening as if the multiplication of territorial entities should respond to the world's demographic explosion.

On the other hand, the bits of good news since the fall of the Berlin Wall — because there are some — come mostly from the evolution of Germany itself. Let's put aside the frightened caricatures of the early 1990s that portrayed then-Chancellor Helmut Kohl under Bismarck's spiked helmet. Let's move past today's economic disputes, which might one day seem rather ridiculous and of marginal importance. The essential is elsewhere.

Germany's reunification is a success, and the country now looks like a pillar of stability in the middle of a Europe that is otherwise undergoing a self-confidence problem. Until now, the meeting of responsible political leaders, from Helmut Kohl and Angela Merkel to Gerhard Schröder, and a people ready to first make sacrifices and then reforms has been a miracle.

But Germany's unquestionable success has not been enough to take the continent that is more and more marred by doubt to a higher level. It's a strange defeat that comes after a victory, which — it's true — was perhaps more of a triumph by default. The democratic world didn't win against the USSR in 1989. It's the totalitarian world that collapsed, a victim of its own contradictions and, as current Chinese and Russian leaders would say, of Mikhail Gorbachev's suicidal naivety.

It's also a strange victory, that of an America that wasted strategically and politically, if not economically, its unique advantages. It did it systematically, from Bill Clinton's failed chances to Barack Obama's shameful hesitations, not to mention George W. Bush's ideological drifts.

On a geopolitical level, will the last quarter century be remembered as the "the passing of the torch" between an exhausted and replete Western world and an emerging one that is hungry for success? Another 25 years, and we will certainly have the answer to that question.