How will the exit affect thousands of British pensioners living in Portugal or Spain who will lose their access to the welfare and health systems? Fifty-three free-trade agreements, which were negotiated by the EU on behalf of all Member States, are also hanging in the balance for the UK.

With their charm and legendary sense of humor, the British directly or indirectly paved the way for a large number of European compromises.

The European Union has decades of experience in overcoming crises and has always emerged stronger after.

I am a champion of trans-Atlantic relations and I do not believe there is any other option available to us than working closely together with America - including Canada. There is no other alliance option, but the same is true for the U.S.

Germany will continue to play a central - perhaps even a more important - role in the European Union. I think that we will all miss the pragmatic approach of the British, however, particularly in those long nights of negotiation.

The problem is: When two governments or institutions in Europe hold differing opinions, it is immediately a crisis.

You can't deepen the European Union against the wishes of the European countries.