General Charles Krulak, former Commandant of the United State Marine Corps, envisioned that our service members would be asked to fight a highly lethal mid-intensity battle and simultaneously execute humanitarian assistance and peacekeeping operations. Further, these operations would occur within three city blocks.

The OneSAF Objective System (OOS) is the next generation simulation system planned to provide the U.S. Army with an entity-level simulation to serve three modeling and simulation domains. The ability of the OOS to provide variable levels of fidelity and support high resolution synthetic environments makes it particularly suited to simulate the precise urban operations described by General Krulak. This paper will discuss the physical, behavioral and environmental models being developed by the OneSAF program. Related modeling of the Contemporary Operating Environment will also be covered.