EXHALT is a relatively simple, uncertainty-sensitive, and optionally stochastic treatment of the halt phase of an operation in which an attacking force is advancing on an objective while its armored vehicles are being interdicted by joint air power and long-range missiles. The model is intended primarily for insight-oriented exploratory analysis, is well suited to a broad scenario space, and is best used as one tool in a family of analyses. EXHALT is easy to extend or simplify because it is modular and is programmed in a visual-modeling environment. Users who program can also change the model itself. EXHALT also includes two conceptually simple agents to represent a commander’s decisionmaking process as he reacts to situational changes in the simulation. EXHALT can be used for either parametric or probabilistic exploratory analysis to assess the effects of uncertainty in theater-level analysis.