Abstract : This monograph discusses U.S. Air Force progress toward implementing sense and respond logistics (S&RL) or, as defined more broadly, sense and respond combat support (S&RCS). As the United States and the Department of Defense transition current forces to a fighting force tailored to the new challenges of the 21st century, responsiveness and flexibility have become fundamental qualities in operational and support forces. Combat support (CS) personnel have traditionally not been integrated into the operational planning cycle and have developed support plans only after the operational plan has been established. To supply essential support materials to operational forces engaged in combat or humanitarian missions, CS forces developed consumption formulas and models, based on relatively long supply chains, that often failed to accurately predict support needs. To compensate, they sent "mountains of supplies" to the war zone to ensure that there would be enough materiel to cover the resupply times. This monograph describes some of the research that has been conducted on the military CS system, focusing on improvements in prediction capabilities, responsiveness of supply chains, and a governing command and control system. Progress has been made in all three areas, and these results have improved Air Force ability to respond to the unique challenges of national defense in the new century. Even so, much remains to be done in the transformation of Air Force CS processes to meet the requirements needed to enable S&RCS capabilities. This monograph tracks this progress, explains the challenges, and plots critical requirements to develop an effective system -- one that senses what is happening on the battlefield and responds to actual requirements rapidly.