The Network Interdiction Problem has a wide variety of applications in areas such as transportation, but, prominently, it has applications in the communications area. This text focuses on problems associated with protecting and attacking computer, transportation, and social networks. These research areas gain importance as the world becomes more dependent on interconnected systems. Optimization models that address the stochastic nature of the problems are an important part of the book and it contains discussion of recent efforts to provide methods for addressing stochastic mixed integer programs. The book is organized with interdiction papers first and the stochastic programming papers in the second part. See the foreword by Roger Wets for further details on the topical coverage. Each chapter represents state-of-the-art research and all chapters have been peer-reviewed.