The role of peacekeeper' has since the end of the Cold War been stretched, redefined and sorely tested, especially in the former Yugoslavia and Somalia leading the public and the Unit' ed Nations Organisation itself to question its efficacy and future. As the former common der of the controversial and high, profile UN force in Bosnia, Lt General Sir Michael Rose here sets out to analyse the challenge to the UN in current and future peacekeeping, drawing on the lessons learnt from on-going deployments of attempting to balance their humanitarian mission with the need for a forceful presence. General Rose stresses the difficulty for the military of performing permanent duty in political vacuums. The presence of UN forces can therefore only be temporary and not a substitute for settlement. He concludes that, although the UN mission in Bosnia has been difficult, costly and painful, its success in sustaining people, containing conflict and creating conditions for negotiations has pushed forward the cause of peacekeeping for 'some 'time to come.