This paper examines the threat posed by Islamic terrorist groups in Southeast Asia and steps being taken by individual nations, regional security organizations, and the United States to combat them. It begins with a brief discussion of the origins of Radical Islam in the region and contextual factors that contributed to its rise and sustainment. Second, the paper will examine individual terrorist groups in the Philippines, Thailand, and Jemaah Islamiyah, a regional terrorist organization operating primarily in Indonesia but with links throughout the region. While this is far from an all-inclusive list of regional terrorist or insurgent groups, these are the primary focus of regional and US concern. The paper also discusses links between Southeast Asian terror groups and al-Qaeda. Next, it examines efforts by individual states and the Association of Southeast Asian Nations to combat this threat, their challenges, and additional steps that need to be taken. Finally, the paper examines the US response to the threat. Using the prism of the National Strategy for Combating Terror it addresses US efforts to identify and defeat terrorists and deny them sanctuary while diminishing the underlying causes of terror and support, describing its effectiveness and identifying additional to be taken to win the war on "Terrors' Second Front.