In the area of stabilization and reconstruction (S & R) operations, this study examines capability gaps and science and technology (S & T) needs and concludes that some areas require renewed emphasis. The Deputy Assistant Secretary of the Army for Research and Technology has been seeking to strengthen the technology base and research planning of Army S & T programs as they relate to S & R operations. By identifying capability gaps and, where appropriate, applying technological approaches to addressing those gaps, the Army should be better positioned to meet its increasingly S & R-focused mission requirements. To support the Army in this effort, the Center for Technology and National Security Policy (CTNSP) at National Defense University (NDU) undertook a study to assess the technological capability gaps in the U.S. Army's ability to conduct S & R operations. The purpose of this study was threefold: (1) through field surveys, interviews, and review of related studies, to identify the technological shortfalls most consistently cited in land force execution of phase IV operations; (2) with respect to these operations, to identify capability gaps and needs and assess them with specific focus on the issue of technology shortfalls; and (3) with the gap analysis in hand, to highlight technology opportunities for consideration by Army S & T leadership. This study is organized along 10 major categories of military capabilities: battle command, armored vehicles in urban environments, situational awareness (SA), intelligence, force protection, unmanned systems, nonlethal capabilities, information operations (IO), training and use of modeling and simulation, and logistics. Within each category, existing and forthcoming Army S & T programs are mapped against stated technology shortfalls and capability gaps. While the issues of technology shortfalls in military capabilities as a whole are important, the overriding orientation of this analysis is focused on S & R operations.