This article argues that civil-military relations should be conceptualized not only in terms of democratic civilian control but also for effectiveness in implementing a spectrum of roles and missions. It also argues that achieving effectiveness requires institutional development as a necessary but not sufficient condition. Currently in Latin America, the focus in civil-military relations remains exclusively on civilian control. While there is a growing awareness of the need for analysis beyond asserting control over the armed forces, so far nobody has proposed or adopted a broader analytical framework. This article proposes such a framework, and employs it to analyze differences among four major South American countries: Argentina, Brazil, Chile, and Colombia. The explanation for the differences identified by use of the framework is found in the incentives of civilian elites in Chile and Colombia, who have recognized serious threats to national security and defense.