The security force framework devised for prosecuting a counterinsurgency campaign is essential. A security framework identifies roles and responsibilities for the different organizations that comprise the overall counterinsurgent force. Part of this overall force is responsible for security in a defined geographical area, or the task of local security, and often takes the form of militias, police, or even military forces. In an effort to understand the factors that most influence the effectiveness of such a force, four historical counterinsurgency case studies are briefly examined to identify any common themes. These factors are then rigorously compared against the Vietnam Conflict and Operation Iraqi Freedom. Five dominant factors emerge that most determine the effectiveness of a local security force. They include the ability to organizationally survive, local recruitment and employment, threat-based training, equipping and mentoring, proper vetting, and mitigating the effects of expansion. These factors are offered as ideas for counterinsurgents to consider during the raising and employment of security forces.