The attacks of 11 September 2001 taught the United States that weak states can pose as great a danger to our national interests as strong states. With this lesson still fresh in the minds of policy makers, and the mixed results of several humanitarian and nation-building missions in the 1990s, considerable interest in redefining US responsibility and capability to rebuild post-conflict nations has arisen. The current struggle to constitute stable governments in both Afghanistan and Iraq has intensified the calls for America to develop a standing nation-building capacity. It is essential that US government policy making bodies, such as the Department of State's Office of the Coordinator for Reconstruction and Stabilization (S/CRS), understand the US Army's current capability to perform stability and reconstruction operations (SRO) missions. This monograph examines what principal activities and roles inherent in SRO, beyond establishing and preserving security, the US Army is currently capable of conducting or coordinating. A secondary question is whether the US Army, as an institution, is suited to govern an occupied territory. The current body of theory, analysis, and commentary on SRO from foreign policy research and analysis institutions, such as the Center for Strategic and International Studies (CSIS), agrees that the US needs to improve its standing SRO capability, but differs significantly with regards to which particular aspects of SRO are the most critical to mission success. Using a modified case study approach, profiles of the Army's planning and performance of SRO in post-World War II Japan and in early Operation Iraqi Freedom are compared. Though the two profiles share many important similarities (e.g. both are instances in which the US decided for various national security reasons to affect fundamental governmental, economic, and societal changes in a foreign country), the differences are striking. These contrasts show that conditions for the peaceful occupation, demilitarization, and democratization of Japan were far more favorable than in Iraq. Likewise, unity of effort in planning and execution of SRO in Japan was superior to that of SRO in Iraq. The SRO profiles also provide context and support to an analysis of past, current, and emerging Joint and Army SRO doctrine that concludes the Army's traditional preference for warfighting missions still heavily influences the way it plans and conducts SRO. In conjunction with the CSIS Post-Conflict Reconstruction Task Framework, the SRO profiles further inform an analysis of the Army's SRO capabilities and capacities. Though the Army has significant shortfalls in all aspects of SRO, including providing security, it remains the US government's most viable and effective SRO capable entity. Finally, the Army must improve its ability to perform the strategically vital role of governing occupied territories, given that it will likely be called upon to do so in the future.