The advent of peacekeeping in the mid-20th century was a significant shift in strategy for conflict resolution.  The failure of collective security under the League of Nations pushed for finding more effective ways for dealing with conflicts. The idea of deploying forces to war torn areas with the purpose of limiting violence gradually evolved and resulted in the establishment of large, complex and costly missions around the world. But how did such operations evolve? Who organises them and how are they deployed? Which criteria should be applied to evaluate their success and failure? What is the future of peace operations? Deihl and Balas seek to answer these fundamental questions and shed some light on the organisation and deployment of peace forces.

Any research on peace operations, in the first place, calls for overcoming the ambiguity of terminology. Terms such as peacekeeping, peace-building, peace-enforcement and peace-operations are commonly used synonymously regardless of clear distinctions. Not so for Deihl and Balas who successfully classify peace missions and expend considerable energies ensuring that the readership fully understands the gravity associated to each dimension.
The second overviews the early development of peace operations and records the striking expansion in the number and types of the tasks they perform. Deihl and Balas rightly observe that peace missions are not deployed to all conflicts in the world and provide a summary of empirical findings showing the necessary conditions for deploying peace operations and the factors which influence their geographic location, size and duration.
The UN has conducted the vast majority of all peace operations but there is a notable drift towards a more serious involvement of regional organisations. The subsequent chapter focuses on explaining the involvement of various international organisations and their roles in the coordination, implementation and financing of peace operations. Deihl and Balas seek to answer which institutional arrangement is most effective and give a comparative assessment of different organisational schemes. They further explore the process of supplying personnel and funding peace operations. The added value consists in the attempt to give an overview of various alternative ways of organising and financing peace missions.
Even though there is a significant number of reports and studies that evaluate the success of peace operations, Deihl and Balas claim that the majority of them is sort of mechanic and defined only by completion of individual tasks with scant regard to long term impacts. They provide a summary of the most recent research on peace operation effectiveness and identify necessary conditions for success. Peace operations are evolving but so are conflicts, making it increasingly difficult to keep track of core issues. In this, the final chapter explores the nature of conflicts in the 21st century and identifies key challenges for the implementation of new peace operations.
This book represents a comprehensive effort to investigate the past and the future of peace operations and provide some guidelines for the further improvements in their overall organisation and implementation. With mounting instability and the increasing number of conflicts over the past few years this book is a useful summary of what has been achieved so far in dealing with conflicts. It is a valuable and highly accessible book for students and scholars as well as policy makers since it provides a context to understanding peace operations and points to larger implications of mission deployment.