Inequality‐based reliability estimates for complex systems

Full‐system testing for large‐scale systems is often infeasible or very costly. Thus, when estimating system reliability, it is desirable to use a method that uses subsystem tests, which are often less expensive and more feasible. This article presents a method for bounding full‐system reliabilities based on subsystem tests and, if available, full‐system tests. The method does not require that subsystems be independent. It accounts for dependencies through the use of certain probability inequalities. The inequalities provide the basis for valid reliability calculations while not requiring independent subsystems or full‐system tests. The inequalities allow for test information on pairwise subsystem failure modes to be incorporated, thereby improving the bound on system reliability. We illustrate some of the properties of the estimates via an example application. © 2013 Wiley Periodicals, Inc. Naval Research Logistics, 2013     

Urban Insurgency

Urban insurgency has generally been presented by analysts and security force personnel as a distinct variant. In contrast, insurgents themselves have often recognized the particular requirements of two dissimilar but related approaches of operation, the urban and rural. Hence they have sought to field approaches and doctrine that exploited the specifics of each. In some cases, simply debating such has led to internal fractures that could not be overcome. More often there has been a deadly rural-urban synthesis that has increasingly challenged security forces.     

Deterring the Undeterrable: Coercion,Denial, and Delegitimization in Counterterrorism

This article argues that deterrence theory can be applied to counterterrorism. Doing so requires broadening the traditional concept of deterrence by punishment, expanding deterrence by denial to include defense, mitigation, and strategic hindrance, and developing deterrence by delegitimization to influence the political, ideological, and religious rationales informing terrorist behavior. In practice, deterring terrorism requires tailoring threats against state and individual facilitators, diffusing the intended consequences of terrorism, and manipulating terrorist self–restraints. When these and other deterrent leverages are applied simultaneously against various actors and processes involved in terrorism, coercion can be achieved.