The Art of War Program places contemporary operations (such as those in Iraq and Afghanistan) in a historical framework by examining earlier military campaigns. Case studies and readings have been selected to show the consistent level of complexity posed by military campaigns throughout the modern era. This paper in the series deals with building irregular security forces. The British and US experience with the use of local, irregular security forces suggest their importance in assisting the host nation government and counterinsurgent forces. Their successful establishment, training, and employment demonstrate the importance of several prerequisites including partnership with an advisory force, consent of the host nation's government to exist, and that the security force is accountable to the local civil authority. Without these prerequisites, the local, irregular security force could risk illegitimacy in the eyes of the populace, the host nation government, and the counterinsurgent. However, partnership does not guarantee a local irregular force's success. The host nation's involvement in the decision to build irregular forces is important from the beginning of the campaign. Through the examination of archival research and primary source interviews associated with the British experience in North-West Frontier and the Dhofar region of Oman, one can start to understand the prerequisites needed to create a successful mentorship force. The paper examines the method of partnership, selection and traits of the advisors, and the host nation government's role in building the Punjab Irregular Force and Frontier Corps in the North-West Frontier in India, the firqat in Dhofar, and the Sons of Iraq.