This book presents a critical review of the performance of UN Peacekeeping with its changing scope from traditional peacekeeping to peacemaking and peace building. In this context while taking the of case studies of UN peace building operations in Rwanda, Mozambique, East Timor and Sierra Leone, he has critically examined the achievements and challenges before the UN peacekeepers in performing their responsibilities in civil war like conditions. This work looks into the critical failures as well as the significant success of the UN peacekeeping forces in very difficult and trying circumstances. The author also gives some modest suggestions for the UN peacekeepers to learn from its past loopholes and challenges and goes ahead with the work of wider peacekeeping in a vibrant manner in any conflict ridden region of the world. India as one of the largest contributor of peacekeepers has played a very pioneering role in such a noble venture.