Insurgency is an organized movement, or group, which aims to overthrow the state or government through violence and subversion. Counterinsurgency is the attempt by a legitimate or state power to defeat and contain an insurgency. Counterinsurgencies create strategic policy to achieve goals. The policy is comprised of tactics, actions taken to achieve a desired goal. These tactics can be violent and coercive, like repression, or constructive, like efforts to rebuild infrastructure. Previous research suggests that repression does not lead to counterinsurgency victory. Despite this, counterinsurgent forces employ some tactic of repression in all phases of all insurgencies occurring after the International Covenant on Political and Civil Rights banned their use in 1976. In fact, this study finds that, on average, repressive tactics are more prevalent than constructive tactics. Why are repressive tactics so prevalent? To answer this overarching question, this inquiry seeks to determine how counterinsurgency decision makers select tactics, structure strategic policy, and improve the odds of success. A theory of strategic conflict policy formation and substitution explains counterinsurgency strategic planning, decision making, and policy execution. The theory proposes two types of policy substitution occur: programmed policy substitution and adaptation policy substitution. Programmed policy substitution asserts an innovative trigger-branch strategic policy structure that substitutes tactics according to the conditions within each conflict. Adaptive policy substitution explains policy shifts that occur after counterinsurgency failures. The project utilizes a mixed methodology approach, applying case study pattern matching, logistic regression, and Cox proportional hazard modeling methods to test hypotheses derived from the theory. The results suggest that counterinsurgencies use repressive tactics to first achieve condition changing goals and then to preserve those new conditions. Repression is triggered by similar conditions to those that cause insurgency onset. The findings support the long-held belief that constructive tactics are associated with counterinsurgency victory. Finally, the study suggests that decision makers with comparable experience in similar conflicts in the area are better at designing strategic policy because they are better at determining threats, predicting conditions, and planning more complex strategies.