Distributed Interactive Simulation (DIS) protocols and standards are being used to enhance the fidelity of the military's family of training models and simulations. This paper will discuss a two-way interface between the Army's Corps Battle Simulation (CBS) and the Extended Air Defesse Simulation (EADSIM) using DIS Protocol Data Units (PDUs). EADSIM is a high fidelity analytic model used by the Services. At the theater level, CBS is integrated with the other Services' models via the Aggregate Level Simulation Protocol (ALSP) to form the Joint Training Confederation (JTC). The basic approach was to develop the ability for EADSIM to play through the CBS model and thus enable both stand-alone CBS and JTC interactions, as the needs of the training audience dictate. The Prairie Warrior '96 exercise demonstrated the use of this concept to focus Army assets on the Theater Missile Defense (TMD) mission. The careful evaluation of the timing constraints required to have the two very different models interoperate was central to the development of the two-way interface since major changes to either of the two models would have been cost prohibitive.