Coalition Provisional Authority in the context of "Sunni Triangle"

The Arab Socialist Ba'ath Party (spelled "Ba'th" or "Baath", "resurrection" or "renaissance"; Arabic: حزب البعث العربي الاشتراكي Ḥizb al-Ba‘th al-‘Arabī al-Ishtirākī), also referred to as the pro-Iraqi Ba'ath movement, is a Ba'athist political party which was headquartered in Baghdad, Iraq, until 2003. It is one of two parties (with identical names) which emerged from the 1966 split of the original Ba'ath Party.

In 1966, the original Ba'ath Party was split in half; one half was led by the Damascus leadership of the Ba'ath Party which established a party in Syria and the other half with its leadership in Baghdad. The two Ba'ath parties retained the same name and maintained parallel structures in the Arab world, but relations became so antagonistic that Syria supported Iran against Iraq during the bloody Iran–Iraq War; it also joined the U.S.-led coalition against Iraq in the Gulf War. The Ba'athists seized power in Iraq for the first time in 1963, but were deposed several months later. The party's regional organisation governed Iraq between 1968 and 2003, for many years under the leadership of Saddam Hussein. The Arab Socialist Ba'ath Party – Iraq Region was banned in 2003 by the Coalition Provisional Authority following the invasion of Iraq by the US and its allies. Other branches of the party have continued to operate.

The occupation of Iraq (2003–2011) began on 20 March 2003, when the United States invaded with a military coalition to overthrow Iraqi president Saddam Hussein and his Arab Socialist Ba'ath Party, and continued until 18 December 2011, when the final batch of American troops left the country. While the United States, the United Kingdom, and Australia were the largest contributors to the coalition, 29 other countries, such as Japan, were involved in the Iraq War in a lesser capacity. Additionally, several private military contractors took part in enforcing the occupation.

It was a period of violence and political turmoil, and saw strong foreign influence exerted on Iraqi politics. In April 2003, the fall of Saddam's government was formally marked by the establishment of the Coalition Provisional Authority, which later appointed and granted limited powers to the Iraq Interim Governing Council. In June 2004, the Iraqi Interim Government was established, ending the international armed conflict that had existed between Iraq (that is, Ba'athist Iraq) and the United States. Following the January 2005 Iraqi parliamentary election, this administration was replaced by the Iraqi Transitional Government. A year later, the Al Maliki I Government took office.

The 2003 invasion of Iraq was the first stage of the Iraq War. The invasion began on 20 March 2003 and lasted just over one month, including 26 days of major combat operations, in which a U.S.-led combined force of troops from the United States, the United Kingdom, Australia, and Poland invaded the Republic of Iraq. Twenty-two days after the first day of the invasion, the capital city of Baghdad was captured by coalition forces on 9 April after the six-day-long Battle of Baghdad. This early stage of the war formally ended on 1 May when U.S. president George W. Bush declared the "end of major combat operations" in his Mission Accomplished speech, after which the Coalition Provisional Authority (CPA) was established as the first of several successive transitional governments leading up to the first Iraqi parliamentary election in January 2005. U.S. military forces later remained in Iraq until their withdrawal in 2011.

The coalition sent 160,000 troops into Iraq during the initial invasion phase, which lasted from 19 March to 1 May. About 73% or 130,000 soldiers were American, with about 45,000 British soldiers (25%), 2,000 Australian soldiers (1%), and about 200 Polish JW GROM commandos (0.1%). Thirty-six other countries were involved in its aftermath. In preparation for the invasion, 100,000 U.S. troops assembled in Kuwait by 18 February. The coalition forces also received support from the Peshmerga in Iraqi Kurdistan.

The Arab Socialist Ba'ath Party – Iraq Region (Arabic: حزب البعث العربي الاشتراكي في العراق, romanized: Ḥizb al-Ba‘th al-'Arabī al-Ishtirākī fī al-'Irāq), officially the Iraqi Regional Branch, was the Iraqi regional branch of the pan-Arab Ba'ath Party, founded in the early 1950s and officially brought to power through the 1968 coup d'état. Rooted in the ideology of Ba'athism, the party combined Arab nationalism, Arab socialism, republicanism, and anti-imperialism, though it developed a distinctive Iraqi character under Saddam Hussein's leadership, often referred to as Saddamist Ba'athism.

From 1968 to 2003, the Ba'ath Party dominated Iraq's political landscape, exerting total control over state institutions, the military, and society through an extensive and often brutal internal security network. It facilitated Saddam Hussein's rise to absolute power in 1979 and played a central role in shaping Iraq's domestic and foreign policies, including the Iran–Iraq War, the invasion of Kuwait, and the Gulf War.Following the U.S.-led invasion of Iraq in 2003, the Ba'ath Party was officially banned by the Coalition Provisional Authority, and thousands of its members were purged from public life in a controversial policy known as de-Ba'athification. Despite the ban, remnants of the party reorganized underground and splintered into factions, most notably those led by Izzat Ibrahim al-Douri and Mohammed Younis al-Ahmed.

The Iraqi Interim Government was created by the United States and its coalition allies as a caretaker government to govern Iraq until the drafting of the new constitution following the National Assembly election conducted on January 30, 2005. The Iraqi Interim Government itself took the place of the Coalition Provisional Authority (and the Iraq Interim Governing Council) on June 28, 2004, and was replaced by the Iraqi Transitional Government on May 3, 2005.

The Iraqi Governing Council (IGC) was the provisional government of Iraq from 13 July 2003 to 1 June 2004. It was established by and served under the United States-led Coalition Provisional Authority (CPA). The IGC consisted of various Iraqi political and tribal leaders who were appointed by the CPA to provide advice and leadership of the country until the June 2004 transfer of sovereignty to the Iraqi Interim Government (which was replaced in May 2005 by the Iraqi Transitional Government, which was then replaced the following year by the first permanent government).

The Council consisted of 25 members. Its ethnic and religious breakdown included 13 Shias, five Sunnis, five Kurds (also Sunnis), one Turkmen and an Assyrian. Three of its members were women.

The Law of Administration for the State of Iraq for the Transitional Period (Arabic: قانون إدارة الدولة للفترة الانتقالية), also called the Transitional Administrative Law or TAL, was Iraq's provisional constitution following the 2003 Iraq War. It was signed on March 8, 2004 by the Iraqi Governing Council. It came into effect on June 28, 2004 following the official transfer of power from the Coalition Provisional Authority (a division of the United States Department of Defense) to a sovereign Iraqi government. The law remained in effect until the formation of the government in May 2006, when it was superseded by the permanent constitution that had been approved by referendum on October 15, 2005.

The TAL was principally drafted by a ten-man committee appointed by the Bush Administration with advice from the United States and United Nations personnel.