The region, home to more than 625 million people, has numerous countries with large Muslim populations, including Indonesia, the world's most populous Muslim-majority nation and the world's third most populous democracy (after India and the United States). The region is home to several longstanding and sometimes violent separatist movements, as well as pockets of Islamist radicalism, which have led to instances of violence over the past 30 years, particularly during the 2000s. Many observers have noted the success of some Southeast Asian governments' efforts combatting violent militancy and degrading some of the region's foremost terrorist groups, including the pan-regional, but largely Indonesian based, Jemaah Islamiyah and the Philippines' Abu Sayyaf. These include helping Indonesia create a centralized antiterrorism unit and providing U.S. advisory troops on the Southern Philippine island of Basilan to help the Armed Forces of the Philippines combat violent groups in the country's deep South. A January 2016 terrorist attack in Jakarta, Indonesia, that killed eight individuals, four of them civilians, demonstrated that militants in the region are seeking support or inspiration from the Islamic State, increasing the risks of terrorism in Southeast Asia—risks that could harm United States citizens or adversely affect U.S. security interests in the region. The Trump Administration has indicated that combatting IS is one of its highest priorities. As Congress considers U.S. policy towards Southeast Asia, it may wish to consider several questions:
What is the nature and extent of radicalization in Southeast Asia, and does it constitute a threat to U.S. interests in the region? Are threat levels affected by the rise of the Islamic State? The vast majority of Southeast Asian Muslims have traditionally subscribed to moderate, syncretic forms of the religion. IS has conducted online recruitment efforts in Indonesia's national language (called "Bahasa Indonesia") and in the Malay language. Analysts estimate that hundreds of Southeast Asians have travelled to the Middle East to fight with IS—just as some did in the late 1990s in Afghanistan with Al Qaeda. Several Southeast Asian governments, including Indonesia, Malaysia, and Singapore, have intensified counterterror efforts since 2014, outlawing calls for support of IS and strengthening policing and border-control efforts. Interests and Policy Responses

The threat of terrorism in or emanating from Southeast Asia has implications for numerous U.S. interests. The United States has coordinated, participated in, or advised a number of global and regional counterterrorism-related policymaking or information exchange bodies in which Asian governments participate:
The Global Counterterrorism Forum is a multilateral body launched in 2011, whose goal is to reduce the vulnerability of people to terrorism by effectively preventing, combating, and prosecuting terrorist acts and countering incitement and recruitment to terrorism; The ASEAN Defense Ministers' Meeting Plus (ADMM Plus) Experts' Working Group on Counterterrorism focuses on strengthening security and defense cooperation in the region; The United Nations Office on Drugs and Crime (UNODC) Terrorism Prevention Branch is responsible for providing assistance to countries toward ratification and implementation of legal instruments against terrorism; The Association of Southeast Asian Nations Regional Forum (ARF) fosters dialogue and consultation on political and security issues, including regional counterterrorism activities; The U.S. Department of State's Regional Strategic Initiative has supported Ambassadors and their Country Teams in developing regional approaches to counterterrorism; The Financial Action Task Force (FATF) is an international policymaking and standard-setting body dedicated to combating money laundering and terrorist financing; FATF-style regional bodies bring together governments in the region to conduct mutual self-assessments and promote best practices; Malaysia and Singapore are members of the Global Coalition to Counter ISIL, an informal grouping that grew out of U.N.-centered efforts to combat IS. U.S. counterterrorism assistance has generally been welcomed by Southeast Asian governments. Country-Level Issues

Southeast Asia is a diverse region, comprising three Muslim-majority states (Indonesia, Malaysia, and Brunei), and several countries with substantial Muslim minorities (the Philippines, Thailand, Singapore, and Burma). Indonesia

Indonesia is Southeast Asia's most populous nation, and the world's largest Muslim-majority state. However, Indonesia has been the site of several of the region's deadliest terrorist attacks: Several bombings in Jakarta and tourist center Bali hit Western targets in the 2000s, and the January 2016 attack in Jakarta was a signal event for many, demonstrating that the rise of the Islamic State has inspired some militants to conduct attacks in Indonesia. However, human rights concerns remain. The rise of the Islamic State and the potential it raises for militant recruitment in Southeast Asia and beyond raises new challenges that may guide U.S. counterterrorism policy. Most analysts assess that terrorist threats in Southeast Asia remain lower than in some other regions.
Southeast Asia is home to more than 625 million people and around 15% of the world's Muslim population. The region has faced the threat of terrorism for decades, but threats in Southeast Asia have never been considered as great as threats in some other regions. However, the rise of the Islamic State poses new, heightened challenges for Southeast Asian governments and for U.S. policy towards the region.
Southeast Asia has numerous dynamic economies and three Muslim-majority states, including the world's largest Muslim-majority nation, Indonesia, which also is the world's third largest democracy (by population) after India and the United States. Although the mainstream of Islamic practice across the region is comparatively tolerant of other religions, Southeast Asia is also home to several longstanding and sometimes violent separatist movements and pockets of Islamist radicalism, which have led to instances of violence over the past 30 years. These were particularly acute during the 2000s, when several attacks in Indonesia killed hundreds of Indonesians and dozens of Westerners. The threat seemingly eased in the late 2000s-early 2010s, with the success of some Southeast Asian governments' efforts to combat violent militancy and degrade some of the region's foremost terrorist groups.
Several Southeast Asian governments, including Indonesia, Malaysia, and Singapore, have intensified counterterror efforts since 2014, outlawing calls for support of the Islamic State and strengthening policing and border-control efforts. Nevertheless, the challenges that governments in the region face were exemplified in January 2016 by a violent attack in Jakarta, Indonesia, that killed eight people, including four civilians.
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.
Threats are evolving with the rise of the Islamic State, which has conducted extensive recruitment in Indonesia's national language (called "Bahasa Indonesia") and in the Malay language widely spoken in the region. Though the number of Southeast Asians who have traveled to the Middle East to fight with the Islamic State is considerably lower than numbers from other regions, such as Europe, North Africa, and South Asia, observers estimate that hundreds of Southeast Asians have joined the fight, raising concerns that battle-trained individuals may return to the region and conduct attacks. Southeast Asia's borders are comparatively porous, raising concerns about trans-border threats that may lead to attacks in third-party states, such as Singapore. This raises the issue of border controls, an important factor for addressing terrorism. Governments in the region have sought better coordination and intelligence sharing—efforts that have been supported by the United States.
The Trump Administration has indicated that combatting terrorism broadly, and IS specifically, is among its highest foreign-policy priorities. This has implications for numerous other U.S. interests, as U.S. policy towards the Asia-Pacific region balances a wide range of security and economic goals. The United States has offered counterterrorism assistance to several Southeast Asian nations. These include helping Indonesia create a centralized antiterrorism unit and providing U.S. troops on the Southern Philippine island of Basilan to help the Armed Forces of the Philippines combat violent groups in the country's deep South. Congress may wish to evaluate the effectiveness of such assistance, and examine funding levels for counterterrorism assistance. Congress may also wish to consider the relationship between counterterrorism assistance and other U.S. goals in the region, including the development of human rights and civil society in Southeast Asia.
This report will be updated periodically.