"When we have the next enlargement of Europe, probably to take in Croatia in 2010 or 2011, we will then need a new treaty to extend the EU to admit the newcomer, " Mr Sarkozy said.

BBC: Sarkozy attacks federalists in EU

It says such a system of "strengthened cooperation" between particular countries, rather than one Europe moving forward at the same speed, will also "put the brakes on the enlargement of the EU to the countries of Eastern Europe".

BBC: European press review

He said that the antidote to "renationalisation" was the enlargement of the European Union and a deepening of Europe's shared functions.

BBC: Europe 'must tackle far right'

Moreover, after the next enlargement to take in countries from Eastern Europe, a Europe of different speeds is surely inevitable.

ECONOMIST: Euro-apartheid?

But if in a year's time the Mladic saga is over, arguments over Kosovo and Montenegro have died away and Europe's foreign ministers have overcome their enlargement fatigue, it might prove to have been the beginning of the end.

ECONOMIST: The Balkans after Milosevic