BBC: David Cameron and Nicolas Sarkozy say the moves will save money without undermining national sovereignty David Cameron has said new treaties on defence and nuclear co-operation with France marked a “new chapter” in a long history of defence co-operation. Speaking alongside French President Nicolas Sarkozy, the UK PM said it would make both countries’ citizens safer and would save money. A centre will be set up in the UK to develop nuclear testing technology and another in France to carry…