When British Prime Minster David Cameron and French President Nicolas Sarkozy signed a Defence and Security Cooperation Treaty just over a year ago, neither could have realised how quickly elements of this closer relationship would be tested. Armed intervention in Libya and economic turmoil in Europe proved early challenges for the treaty's aims. Indeed such has been the stress of recent weeks that a long-planned summit on 2 December to review and renew progress on defence cooperation was postponed. Instead a meeting between the two leaders focused on Europe's economic travails.