More than 11 years after the 9/11 attacks and 10 years after the October 2002 Bali bombings, the need for a comprehensive assessment of what the countries in Southeast Asia have achieved is overdue. We need to consider whether the strategies against both the domestic and transnational terrorist and extremist threat have been appropriate and have yielded desired results. The aim of this book is to make a comprehensive assessment of the threats of terrorism and extremism in the region and of the policies and practices adopted by the regional countries to counter the same. It is also necessary to evaluate if the region has become a safer place after the decade-long fight. Most importantly, it is time to ask if we need a rethink or develop a new strategy to contain and manage the threats of terrorism and extremism.