The European Union was supposed to bring member states closer together, politically and economically.
The pace of integration was sometimes faster than European electorates were prepared to accept. But as long as Europe remained prosperous, voters went along with it.
But over the past few years, things have started to change. The EU has had to weather crisis after crisis, revealing just how difficult it is to achieve unity among 28 different countries.
And with Europe's politicians seemingly unable to overcome their differences, further integration no longer seems such an attractive idea.
It has led to a feeling that solidarity is being eroded. And that the European project, devised to bring peace and stability to a continent ravaged by war, may be in danger.
So, is the dream of an "ever closer union" coming to an end?
Presenter: Sami Zeidan
Claude Moraes - Labour member of the European Parliament for London and deputy leader of the European Parliamentary Labour Party.
Florian Hartleb - A lecturer at Eichstatt University.
Daniel Schade - Deputy Chairman of the Project for Democratic Union and Specialist on European policy.
Source: Al Jazeera