There is opportunity in austerity. Britain and France are putting pen to parchment on a new defence treaty – the first of its kind since the Treaty of Dunkirk in 1947. Strange as it may seem, the two countries were fretting then about German resurgence. Now, they want to hold on to a role in a world where power is shifting from the Atlantic to the Pacific.

The treaty has been born of shared fiscal adversity. Half a dozen linked agreements envisage joint training and deployment of troops, collaboration in unmanned aircraft, more inter-operability, and shared high-technology research and procurement.

David Cameron and Nicolas Sarkozy will also put their names to a separate, unprecedented treaty on nuclear co-operation. The two countries will share sensitive test data to develop a new generation of nuclear warheads.