From the Summary: "There are several factors that characterize the terrorism threat in Southeast Asia. The region's largest Muslim-majority nations, Indonesia and Malaysia, have long been known for moderate forms of Islam and the protection of religious diversity--policies that have widespread popular support but which raise resentments among small numbers of conservative actors. In other Southeast Asian countries with substantial Muslim populations, including the Philippines and Thailand, simmering resentments in Muslim-majority regions have been fed by perceived cultural and economic repression, leading to separatist movements that have posed threats to domestic groups--and in the case of the Philippines, to Western targets."
CRS Report for Congress, R44501
Congressional Research Service: https://crsreports.congress.gov/