This monograph addresses how combined arms organizations should be formed in our Army today. Specifically, it focuses on the question, "what arms, if any, should be combined organically at battalion level?" This issue is important because our AirLand Battle doctrine considers combined arms to be essential to winning on the modern battlefield. Therefore, we should investigate the best means by which to maximize the potential of the organizations. The monograph first examines the theoretical foundation for combined arms. Next, both historical and contemporary evidence are examined to derive a set of criteria that can be used to analyze the four selected arms: infantry, armor, artillery, and engineer in terms of the AirLand battlefield environment. The five selected criteria are frequency of interaction, competence of commander to synchronize the effects of weapon systems, scarcity of resources, cope of tactical missions, and similarity in range and mobility. These criteria are key factors that should be used whenever determining how an organization should be structured organically. Conclusions concerning the structure of a combined arms battalion are drawn from an analysis of these dominant criteria. This monograph concludes that infantry and armor are the only two arms that should be combined organically at battalion level. By combining these two arms permanently, it is almost certain that the combat potential of the organizations will increase.