This chapter uses a framework developed to analyse civil-military relations in terms of both democratic civilian control and effectiveness. The focus is on effectiveness in security. As the achievement of effectiveness only makes sense in terms of the roles and missions implemented by the security forces in Chile, these will be spelled out. Further, to appreciate the achievement in Chile, the chapter focuses on comparative analysis with other countries that are relatively successful in achieving both democratic civilian control and effectiveness. The case studies incorporated are Colombia, Portugal, and the United States. Since few roles and missions can be proven to be successful, the focus must necessarily be on the essential elements for effectiveness; that is, they are necessary if not sufficient. Consequently, the implementation of a military strategy or policy requires an analysis as to whether these essential elements are present. In each country, strategy has some significance, relative to other cases where they have none, and there are some implementing institutions as well as some resources. The chapter concludes that control is relatively easy to conceptualise and define, and to identify the relevant institutions, and in Chile they are present and functioning. The very dynamic ‘adjustment’ of different roles and missions raises the question as to whether the current mix of strategies to resources will continue to put Chile at the top of the military effectiveness hierarchy.