The author has carried out a searching review of the principles promulgated by the British and American Defence Forces, in order to assess their continuing validity and relevance to warfare in the late 1990s and the 21st century. Recognising that principles will be applied by commanders to meet specific situations in the field he extends this study to embrace leadership and training for leadership and command. In the final chapter he addresses the moral responsibilities of those exercising command of their fellow countrymen and other assigned forces.