Otterbein notes that ethnocentrism and the enhancement of intragroup cohesion are well documented effects of warfare, as well as factors bringing it about through military preparedness. Approaching the problem of the relationship between disarmament and development from R. Bigelow’s framework, this chapter focuses on processes resulting from cooperation and competition in order to discover the means to defuse competition and conflict and to enhance cooperation. Development slows when warfare becomes a major political focus and armament leaves fewer resources for development. Focusing on the mental and social preparation for armed deeds among Jibaro Indians, R. Karsten describes a range of processes designed to promote the shift to warlike attitudes and actions. While Jibaro warfare differs in kind and in detail from most other types of warfare and especially those of technologically highly developed states, the general strategy of preparation has parallels in other communities.