Intertwined in virtually all aspects of military decision-making -- from what weapons governments should buy to how soldiers should use them -- is modeling. This volume, now in a third and substantially revised edition, provides the most useful overview of the subject by some of the most notable figures in the field. The editor, a navy captain who has written authoritatively on a number of subjects (naval tactics in particular) sets the tone in a masterly overview that stresses, as do many of the essays that follow, the limitations of these artificial and simplified representations of the warrior's world. Driven too frequently by underlying assumptions about quantitative factors (firepower and numbers) rather than qualitative realities (morale, cohesion, coordination) military models can mislead those who put excessive faith in them -- as the wildly pessimistic projections of American casualties in the Gulf War demonstrated. A work that, if read with care, would do much to reduce the simple faith placed by civilian and soldier alike in these ubiquitous attempts to distill reality into equations.