How does the U.S. military understand and apply the center of gravity concept in the contexts of theory, doctrine, and planning for the conduct of operations? In particular, does the center of gravity serve as an effective tool when applied in accordance with current military doctrine and other non-doctrinal methodologies, and how does its use help reveal causal relationships and account for the emergent properties of complex systems? Academics and military practitioners have debated the meaning and usefulness of the concept of centers of gravity since Clausewitz introduced it in the early nineteenth century. In order to understand and apply the joint doctrine for operational design as described in Joint Publication 50, Joint Operations Planning, the military must come to a consensus on the meaning, uses, and applicability of centers of gravity. So far this consensus has not formed, and as time passes it appears even more elusive. With the U.S. Army currently undertaking a major reworking of its operational doctrine, an opportunity exists to clarify the concept and its practical application; otherwise the term could end up trapped in the same conceptual quagmire that led to the death of "Effects Based Operations" (EBO) as a joint doctrinal concept. INTRODUCTION * Hypothesis * METHODOLOGY * Systems Thinking Understood * Mechanisms of Collective Behavior (Patterns) * Multi-scale Perspective * The Evolutionary Process that Creates Complex Systems * Nature of Purposive or Goal-Directed Behavior * ANALYSIS * Battles of Granicus, Issus, and Gaugamela * Jena-Auerstadt 1806 * Vietnam War (The 1970 Cambodian Campaign) * Operation Desert Storm * CONCLUSIONS AND RECOMMENDATIONS * Conclusions * Implications and Recommendations * BIBLIOGRAPHY