It's hard to imagine a tougher year for Europe's union. Pressure to pull the EU's 28 countries tighter together instead risks pushing it farther apart. So the most powerful proponents of European unity — the leaders of Germany and France — are trying to come to its rescue.
The highly unusual appeal Wednesday by German Chancellor Angela Merkel and French President Francois Hollande to the European Parliament may not be enough to heal the divisions within the European Union caused by the influx of refugees, debt crises, and encroaching nationalist sentiment.
Merkel and Hollande, children of post-war Europe and symbols of its reconciliation, will need forceful words to counter skepticism and disillusionment among many lawmakers and voters.
"Europe is again facing a test," Merkel said in her weekly video message Saturday. "This test is: how do we deal with the refugees? How do we find a common European answer? And above all, how can we as Europe together combat what is causing people to flee?"
Merkel said that speaking alongside Hollande in Strasbourg — a city their countries long fought over and that now houses European institutions — would be "a moving moment."
It's the first such joint appearance since 1989, when West German Chancellor Helmut Kohl and French President Francois Mitterrand spoke in Strasbourg days after the fall of the Berlin Wall. With Germany heading toward unification, they stressed their commitment to speed up construction of the EU.
The bloc was conceived to end centuries of war through open trade and increased prosperity, and it's also been a way for Europe to stay globally relevant. Germany and France have played a leading role to keep the 28-nation bloc united despite major differences of views among European leaders.
Since 2014, the EU has faced the Ukrainian conflict at its eastern border, Greece's resurgent debt crisis, terrorist attacks in Paris and Brussels, threats that Britain could leave the EU — and the biggest wave of migrant arrivals since World War II.
Elections for European parliamentarians last year produced a rise of populist and far-right parties, including members of neo-Nazi movements in Germany and Greece.
Wednesday offers a prime opportunity for EU critics to assail Hollande and Merkel for pulling the EU ever closer together — especially Marine Le Pen, a French presidential hopeful with strong anti-immigrant views who's scheduled to take the floor as head of a new group in Parliament for far-right politicians.
Hollande and Merkel want to show that France and Germany are committed to strengthening Europe, French officials said. They're expected to push for solidarity between European peoples and openness toward refugees.
Merkel, whose country has taken in most of the hundreds of thousands of refugees arriving this year, has stuck to a positive message despite strains on authorities' ability to provide housing. France has been slow to respond but is catching up. Some European countries, particularly in the formerly communist east, don't want to take in any at all.
Europe can still take heart that refugees see it as a beacon of hope and a brighter future, ample proof that the European Union was much more than a succession of failures as many of its critics want to make out.
The conservative German Chancellor and the Socialist French president, though of different political camps, have developed a strong personal relationship. After extremist attacks on Paris in January, Merkel was the first to call Hollande.
"This is a historic visit for historically difficult times. The European union is facing immense challenges and requires strong commitment by its leaders," European Parliament president Martin Schulz said when he announced the visit.
King Felipe VI of Spain will also address the European Parliament on Wednesday, almost 30 years after Spain's accession to the EU — and as his own country is facing a rising independence movement in Catalonia.