The majority of the world's Muslim population follows the Sunni branch of Islam, and approximately 10%-15% of all Muslims follow the Shiite (Shi'ite, Shi'a, Shia) branch. Shiite populations constitute a majority in Iran, Iraq, Bahrain, and Azerbaijan. Sunnis and Shiites share most basic religious tenets. However, their differences sometimes have been the basis for religious intolerance, political infighting, and sectarian violence. This report includes a historical background of the Sunni-Shiite split and discusses the differences in religious beliefs and practices between and within each Islamic sect as well as their similarities. The report also relates Sunni and Shiite religious beliefs to discussions of terrorism and sectarian violence that may be of interest to Congress.

None

This report discusses US military operations in Iraq. Iraq's chemical, biological, and nuclear weapons programs, together with Iraqi long-range missile development and support for al-Queda terrorism, were the primary justifications put forward for military action.

This report provides background and analysis on the politics of Iraq, including its communities, its governing personalities and factions, security forces and militias, and the government's human rights record.

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 briefly discusses different options available for confronting the Islamic State (IS, formerly known as ISIS or ISIL) with the use of military force. The examines the legal considerations relevant to each approach.

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.

None

This report discusses the concerns for the Middle Eastern governments and the United States regarding the armed offensive of the Islamic State (IS, also known as ISIL or ISIS) in northern and western Iraq and northeastern Syria.

This report discusses the current political and social climate of Iraq, specifically in regards to the influence of the U.S. military presence over recent years. This report addresses planned and possible future efforts under the Obama Administration, including the scheduled gradual troops withdrawal. This report also discusses the continued tensions between various Iraqi sociocultural groups.

Operation Iraqi Freedom overthrew Saddam Hussein’s regime, but Iraq remains unstable because of Sunni Arab resentment and a related insurgency, compounded by Sunni-Shiite violence that a January 2007 national intelligence estimate says has key elements of a “civil war.” Mounting U.S. casualties and financial costs — without clear signs of security progress — have intensified a debate within the United States over whether to wind down U.S. involvement without completely accomplishing initial U.S. goals.

This report presents casualty data compiled by the Department of Defense (DOD), as tallied from the agency’s press releases.

The following casualty data was compiled by the Department of Defense (DOD), as tallied from the agency's press releases. Included are statistics on fatalities during Operation Iraqi Freedom, which began on March 19, 2003, and is ongoing, as well as on the number of fatalities since May 1, 2003, plus statistics on those wounded, but not killed, since March 19, 2003. Statistics may be revised as circumstances are investigated and as all records are processed through the U.S. military's casualty system.

The “oil-for-food” program (OFFP) was the centerpiece of a long-standing U.N. Security Council effort to alleviate human suffering in Iraq while maintaining key elements of the 1991 Gulf war-related sanctions regime. In order to ensure that Iraq remained contained and that only humanitarian needs were served by the program, the program imposed controls on Iraqi oil exports and humanitarian imports. All Iraqi oil revenues legally earned under the program were held in a U.N.-controlled escrow account and were not accessible to the regime of Saddam Hussein.

The major challenges to coalition forces are now quelling a persistent Iraqi resistance movement and training sufficient Iraqi forces to assume responsibility for the nations domestic security. This report discusses military planning and operations in Iraq.