This paper examines the purpose, consequences, and lessons to be drawn from the security operations conducted by Indonesian forces in Aceh since 1990. As the vested interests of the TNI and its emphasis on a military solution have contributed to an escalation of the conflict, it argues that the military requires an exit strategy to be followed by socio-economic reconstruction. The paper is divided into four sections. The first outlines the root causes of the conflict and discusses military operations during the period 1990?98 when Aceh was designated a Military Operations Area (Daerah Operasi Militer; DOM). Security operations in Aceh between the downfall of Suharto?s New Order regime in May 1998 and May 2003, when the government finally decided to impose martial law and launch a full-scale military crackdown in the province are explored in the second section. The third explores the conduct of the counterinsurgency operation during the first six months of martial law in the province. The final section looks at how the government?s failure to consider the wider context of the conflict undermines the relative gains achieved on the military front. While security operations during the 1990s contributed to the aggravation of the problem??due primarily to the failure of Indonesia?s military to protect human rights??the military operation since May 2003 will not end the conflict in Aceh if the government fails to undertake non-military measures to address the root causes of the problem in the province.This is the third publication in Policy Studies, a peer-reviewed East-West Center Washington series that presents scholarly analysis of key contemporary domestic and international political, economic, and strategic issues affecting Asia in a policy relevant manner.