"In explaining the decision to invade Iraq and oust Saddam Hussein from power, the Administration asserted, among other justifications, that the regime of Saddam Hussein had a working relationship with the Al Qaeda organization. The Administration stated that the relationship dated to the early 1990s, and was based on a common interest in confronting the United States. […] Another pillar of the Administration argument, which has applications for the current U.S. effort to stabilize Iraq, rested on reports of contacts between Baghdad and an Islamist Al Qaeda affiliate group, called Ansar al-Islam, based in northern Iraq in the late 1990s. Although the connections between Ansar al-Islam and Saddam Hussein's regime were subject to debate, the organization evolved into what is now known as Al Qaeda in Iraq (AQ-I). AQ-I has been a key component of the Sunni Arab-led insurgency that frustrated U.S. efforts to stabilize Iraq, but there is debate about how large and significant a component of overall violence was carried out by AQ-I. […] Analysis of the broader implications of AQ-I might depend on the degree to which AQ-I is in contact with the remaining structures of the Al Qaeda organization that organized the September 11, 2001 attacks on the United States."
CRS Report for Congress, RL32217