Another war between France and Germany is unthinkable 40 years on from the Elysée Treaty of 1963. The treaty deepened what French and German leaders had already agreed when the European Coal and Steel Community was set up in 1951, the European Economic Community and the European Atomic Energy Community in 1957. In the same way the Franco-German agreements announced yesterday in Versailles will profoundly affect the future of the European Union as it decides how to organise its politics for the next generation.
These agreements must, of course, be set against the three wars they fought between 1870 and 1945. Two of them became world wars in which many millions died. Hence the moving prologue to the Coal and Steel treaty by the rulers of France, Germany, Belgium, Italy, Luxembourg and the Netherlands in 1951. They "resolved to substitute for age-old rivalries the merging of their essential interests; to create, by establishing an economic community, the basis for a broader and deeper community of peoples long divided by bloody conflicts; and to lay the foundations for institutions which will give direction to a destiny henceforward shared."
These famous words were echoed in yesterday's declaration, which said "France and Germany are linked by a shared destiny. Our common future is inseparable from that of a more integrated and enlarged European Union." A raft of proposals and new initiatives has been attached to this 40th anniversary. The most publicised and controversial one puts the case for a dual presidency of the EU - a Commission president elected by the European Parliament and confirmed by political leaders of the member-states; and a president of the European Council appointed by these leaders for a fixed term instead of the existing six-month rotating system. It has been convincingly criticised, especially by smaller states, as likely to undermine the Commission and bolster the role of the larger ones; but, given its provenance, it sets the agenda for political debate on this subject over coming months.
Also contained in the Franco-German plan is much closer co-operation over EU foreign policy, security, defence and criminal matters. The seriousness of their intent is underlined by reinforcement of their own bilateral relations, including radical plans for joint citizenship and closer cultural co-operation.
Franco-German relations over these 40-50 years have been an elite rather than a popular project - not unlike European integration itself. Increasingly, however, both these projects will have to engage citizens. France and Germany will also have to demonstrate anew that they retain the capacity to make a difference in a much larger European Union.