This is all the more urgent given Mr Cameron’s decision to advance again the case for British military action in Syria against a group whose victims in Paris include one Briton. As we report, Mr Cameron’s team believe that enough Labour MPs are willing to defy their leader to support such action, giving Mr Cameron a parliamentary majority despite the reservations of some Tory backbenchers. Those reservations are based on a desire for a comprehensive strategy for Syria after Isil and after President Bashar al Assad. That is a reasonable desire and one that the Government should satisfy – but not at the cost of delaying the urgent business of destroying an organisation that now demonstrably threatens our security.