This report discusses U.S. and European assessments of and responses to the foreign fighter phenomenon. It focuses on government policies primarily in Western European countries and analyzes EU measures to counter the foreign fighter threat given the EU's largely open internal borders and that 23 EU member states belong to the U.S. Visa Waiver Program.

This report briefly discusses the Syria-based terrorists referred to as the "Khorasan Group" and the U.S. airstrikes conducted against them in late September 2014.

This report reviews the authority granted in H.J.Res. 124 and explores similarities and differences among the H.J.Res. 124 authority, the President's requests, and other proposals that may be considered by Congress, including during anticipated consideration of FY2015 full-year appropriations or defense authorization (H.R. 4435/S. 2410) legislation.

This report reviews the authority granted in H.J.Res. 124 and explores similarities and differences among the H.J.Res. 124 authority, the President's requests, and other proposals that may be considered by Congress, including during anticipated consideration of FY2015 full-year appropriations or defense authorization (H.R. 4435/S. 2410) legislation.

This report provides background on the Islamic State organization, discusses its goals, operations, and affiliates, reviews U.S. legislative and policy debates, and reviews relevant legislation from the 114th and 115th Congresses.

This report provides background on the Islamic State organization, discusses its goals, operations, and affiliates, reviews U.S. legislative and policy debates, and describes select FY2017 legislative proposals.

This report provides background on the Islamic State organization, discusses its goals, operations, and affiliates, reviews U.S. legislative and policy debates, and describes select FY2017 legislative proposals.

This report provides background on the Islamic State organization, discussing its goals, operations, and affiliates, as well as analyzing related U.S. legislative and policy debates.

This report discusses the The Islamic State (IS, aka the Islamic State of Iraq and the Levant, ISIL/ISIS, or the Arabic acronym Daesh), which is a transnational Sunni Islamist insurgent and terrorist group that controls large areas of Iraq and Syria, has adherents in several other countries, and disrupts regional and international security with violence and terrorism.

This report discusses reports of a mass casualty chemical weapons attack in the suburbs of Damascus and the possible punitive U.S. military action against the Asad regime.

This report discusses the recent conflict in Syria including an overview of the situation, information about anti- and pro-Asad forces, background on chemical weapons and disarmament, plans for U.S. policy and assistance, and a general sense of the future outlook.

This report discusses the recent conflict in Syria including an overview of the situation, information about anti- and pro-Asad forces, background on chemical weapons and disarmament, plans for U.S. policy and assistance, and a general sense of the future outlook.

This report discusses the recent conflict in Syria including an overview of the situation, information about anti- and pro-Asad forces, background on chemical weapons and disarmament, plans for U.S. policy and assistance, and a general sense of the future outlook.

This report discusses the recent conflict in Syria including an overview of the situation, information about anti- and pro-Asad forces, background on chemical weapons and disarmament, plans for U.S. policy and assistance, and a general sense of the future outlook.

This report discusses the recent conflict in Syria including an overview of the situation, information about anti- and pro-Asad forces, background on chemical weapons and disarmament, plans for U.S. policy and assistance, and a general sense of the future outlook.

This report discusses the continuing conflict in Syria including recent regime losses in confrontations with forces of the Islamic State (IS, aka the Islamic State of Iraq and the Levant or ISIL/ISIS) in northeastern Syria. The report also covers Syrian chemical weapons disarmament and U.S. policy.

This report discusses the ongoing conflict in Syria and provides an overview of U.S. Policy responses. The rise of the insurgent terrorist group known as the Islamic State (IS, aka the Islamic State of Iraq and the Levant or ISIL/ISIS) and Russia's military intervention on behalf of the Syrian government have reshaped debates over U.S. policy toward the ongoing civil conflict in Syria, now in its fifth year.

This report discusses the continuing conflict in Syria including recent regime losses in confrontations with forces of the Islamic State (IS, aka the Islamic State of Iraq and the Levant or ISIL/ISIS) in northeastern Syria. The report also covers U.S. policy responses to the conflict.

This report discusses the current crisis involving the Islamic State, which is a transnational Sunni Islamist insurgent and terrorist group that has expanded its control over areas of parts of Iraq and Syria since 2013.

This report discusses the current crisis involving the Islamic State, which is a transnational Sunni Islamist insurgent and terrorist group that has expanded its control over areas of parts of Iraq and Syria since 2013.

This report discusses the current crisis involving the Islamic State, which is a transnational Sunni Islamist insurgent and terrorist group that has expanded its control over areas of parts of Iraq and Syria since 2013.

This report addresses select legal questions raised by the use of military force against Islamic State (IS). Questions addressed in this report include potential sources (and limitations) of presidential authority to use military force against the Islamic State without congressional authorization; the potential relevance of the 2002 Authorization for Use of Military Force Against Iraq (2002 Iraq AUMF; P.L. 107-243) and the 2001 Authorization for Use of Military Force (2001 AUMF; P.L. 107-40); the applicability of the United Nations Charter to ongoing U.S. military strikes in Iraq and any prospective strikes against IS forces in Syria; and the constraints imposed by the War Powers Resolution upon U.S. military action that has not been authorized by Congress.

This report discusses the President's plan for U.S. involvement in Syria in the future and the five main goals the U.S. hopes to accomplish there.

This report discusses the ongoing conflict in Syria and U.S. policy regarding the conflict and potential resolutions.