New, innovative methods will be required to get through to this generation of young people, for whom text messaging and the Internet are integral parts of daily life.
Mr Brennan is believed to have been at the heart of trying to formalise the rules of this new war through the creation of a "playbook": a set of criteria and methods for how decisions of life and death should be made.
John Brennan is believed to have been at the heart of trying to formalise the rules of this new war through the creation of a "playbook": a set of criteria and methods for how decisions of life and death should be made.