The Department of Defense is motivated by both opportunities and necessity to transform the force over the years ahead by exploiting modern technology and operational concepts associated with the revolution in military affairs, and by making related organizational changes. This documented briefing provides a background review describing a broad transformation strategy, then discusses and illustrates how analysis supported by models and simulations (including gaming) can supplement and guide empirical work such as joint experiments. The approach is illustrated for the problem of halting an invading army, with long-range precision fires playing a major role. A great deal of insight about the general problem can be obtained from analysis at different levels of resolution with a family of models. This process, in turn, identifies important kinds of information that can be obtained only from empirical work such as joint field experiments. The recommended