France and Germany recently issued a joint postage stamp as part of a yearlong celebration of the 50th anniversary of the Elysee Treaty, the landmark agreement between the two former enemies.
The stamp is identical, except for one telling difference. In each country, it bears a picture of a man and woman, side by side, peering through lenses colored in blue-white-red and black-red-gold. But the French stamp costs 80 euro cents, while its German twin sells for only 75.
In a year loaded with symbolic gestures and 4,000 commemorative events, including Tuesday's joint session of Parliament, joint cabinet dinner and a concert, that 5-cent disparity is a reminder that despite the decades of friendship and enormous day-to-day cooperation, significant, often devilish, differences persist.
De Gaulle once described Europe as "a coach with horses, with Germany the horse and France the coachman." Since he signed the treaty with the German chancellor Konrad Adenauer in 1963, successive governments in both countries have struggled to overcome, or overlook, what divides them.
But the relationship has never been as close as some hoped. While the German news media celebrated Tuesday's anniversary of a treaty that has been a cornerstone for the European Union and German prosperity, the tone from France was harsher. Le Figaro called it "a friendship broken down," foundering on "diplomatic and economic tensions," while Le Monde called the event "a festival of hypocrisy."
The critical matter, however, is that war between the two peoples, who murdered one another for centuries, seems as inconceivable now as the Spanish Inquisition.
"Coming from a long history of conflict and war, they have succeeded in intertwining themselves so closely that today one can no longer imagine it any other way than both partners working closely together," said Georg Link, the German foreign minister's commissioner for Franco-German cooperation.
Chancellor Angela Merkel, a conservative, and President Franois Hollande, a Socialist, began the festivities on Monday here, with a question-and-answer session with university students from both countries. Sitting side by side, they appeared at ease for the first time since Mr. Hollande came to power last May, exchanging jokes and using first names — a public first, and a telling shift.
(Read More: What Makes Angela Merkel Tick)
Yet, even if the two succeed in establishing a better relationship, the tensions between centralized, statist France and federal Germany are real and will persist. They involve European issues like the euro zone crisis and the failed merger of the aerospace giants EADS and BAE Systems, as well as foreign policy matters, like the obvious disagreements over military engagements in Libya and now Mali.