The National Security Council has been responsible for the collective development of this National Security Strategy and for the associated Strategic Defence and Security Review which builds on it. This work is historic: no government has previously carried out a detailed review of all its security and defence capabilities. Nor has there been a full Strategic Defence Review since the world-changing events of 11 September 2001. We need to take full account of our experience of the previous decade, both at home and abroad and be prepared for the security needs of the future.