Part of the debate over the Bush Administration decision to use military action to overthrow the regime of Saddam Hussein centers on whether or not that regime was allied with Al Qaeda. In building an argument that the United States needed to oust Saddam Hussein militarily, the Administration asserted that Iraq constituted a gathering threat to the United States because it continued to develop weapons of mass destruction (WMD) that it could potentially transfer to international terrorist groups, including Al Qaeda, with which Iraq was allied. This combination produced the possibility of a catastrophic attack on the United States, according to the Administration. The first pillar of the Administration argument for ousting Saddam Hussein—its continued active development of WMD—has been researched extensively. After the fall of the regime in April 2003, U.S. forces and intelligence officers in an "Iraq Survey Group" (ISG) searched Iraq for evidence of WMD stockpiles. A "comprehensive" September 2004 report of the Survey Group, known as the "Duelfer report," said that the ISG found no WMD stockpiles or production but said that there was evidence that the regime retained the intention to reconstitute WMD programs in the future. The formal U.S.-led WMD search ended December 2004, although U.S. forces have found some chemical weapons caches left over from the Iran-Iraq war. The UNMOVIC work remained formally active until U.N. Security Council Resolution 1762 terminated it on June 29, 2007. The second pillar of the Administration argument—that Saddam Hussein's regime had links to Al Qaeda—is relevant not only to assess justification for the invasion decision but also because an Al Qaeda affiliate (Al Qaeda in Iraq, or AQ-I) became a key component of the post-Saddam insurgency among Sunni Arabs in Iraq. The Administration has maintained that the Al Qaeda presence in Iraq, fighting alongside Iraqi insurgents from the ousted ruling Baath Party, members of former regime security forces, and other disaffected Iraqi Sunni Arabs, demonstrates that there were pre-war linkages. On the other hand, most experts believe that Al Qaeda and other foreign fighters entered Sunni-inhabited central Iraq after the fall of Saddam Hussein, from the Kurdish controlled north and from other Middle Eastern countries. These foreign fighters are motivated by an anti-U.S. ideology and a target of opportunity provided by the presence of U.S. forces there, rather than longstanding ties to the former Iraqi regime, according to this view. On March 17, 2003, in a speech announcing a 48-hour deadline for Saddam Hussein and his sons to leave Iraq in order to avoid war, President Bush said: ...the [Iraqi] regime has a history of reckless aggression in the Middle East. It has a deep hatred of America and our friends. And it has aided, trained, and harbored terrorists, including operatives of Al Qaeda." The Administration argument for an Iraq-Al Qaeda linkage had a few major themes: (1) that there were contacts between Iraqi intelligence and Al Qaeda in Sudan, Afghanistan, and Pakistan dating from the early 1990s, including Iraq's assistance to Al Qaeda in deployment of chemical weapons; (2) that an Islamist faction called Ansar al-Islam (The Partisans of Islam) in northern Iraq, had ties to Iraq's regime; and (3) that Iraq might have been involved in the September 11, 2001 plot itself. Of these themes, the September 11 allegations are the most widely disputed by outside experts and by some officials within the Administration itself. Some Administration officials, including President Bush, have virtually ruled out Iraqi involvement in the September 11 attacks while others, including Vice President Cheney, have maintained that the issue is still open. Secretary of State Powell presented the Administration view in greater public detail than any other official when he briefed the United Nations Security Council on Iraq on February 5, 2003, although most of that presentation was devoted to Iraq's alleged violations of U.N. requirements that it dismantle its weapons of mass destruction (WMD) programs. According to the presentation: Iraq and terrorism go back decades.... But what I want to bring to your attention today is the potentially more sinister nexus between Iraq and the Al Qaeda terrorist network, a nexus that combines classic terrorist organizations and modern methods of murder. Iraq today harbors a deadly terrorist network headed by Abu Musab Al-Zarqawi, an associate and collaborator of Osama bin Laden and his Al Qaeda lieutenants. Going back to the early and mid-1990s, when bin Laden was based in Sudan, an Al Qaeda source tells us that Saddam and bin Laden reached an understanding that Al Qaeda would no longer support activities against Baghdad.... We know members of both organizations met repeatedly and have met at least eight times at very senior levels since the early 1990s.... Iraqis continued to visit bin Laden in his new home in Afghanistan [after bin Laden moved there in mid-1996].... From the late 1990s until 2001, the Iraqi embassy in Pakistan played the role of liaison to the Al Qaeda organization ... Ambition and hatred are enough to bring Iraq and Al Qaeda together, enough so Al Qaeda could learn how to build more sophisticated bombs and learn how to forge documents, and enough so that Al Qaeda could turn to Iraq for help in acquiring expertise on weapons of mass destruction. Secretary Powell did not include in his February 5, 2003, briefing the assertion that Iraq was involved in the September 11 plot. Some analysts suggest the omission indicates a lack of consensus within the Administration on the strength of that evidence. In a January 2004 press interview, Secretary Powell said that his U.N. briefing had been meticulously prepared and reviewed, saying "Anything that we did not feel was solid and multi-sourced, we did not use in that speech." Additional details of the Administration's argument, as well as criticisms, are discussed below. Post-Saddam analysis of the issue has tended to refute the Administration argument on Saddam-Al Qaeda linkages, although this issue is still debated. The report of the 9/11 Commission found no evidence of a "collaborative operational linkage" between Iraq and Al Qaeda. In his book "At the Center of the Storm" in May 2007 (Harper Collins Press, pp. 341-358), former CIA Director George Tenet indicated that the CIA view was that contacts between Saddam's regime and Al Qaeda were likely for the purpose of taking the measure of each other or take advantage of each other, rather than collaborating. Others note, however, that some of Tenet's pre-war testimony before Congress was in line with the prevailing Administration view on this question, contrasting with the views in his book. In March 2008, a study by the Institute for Defense Analyses, written for the U.S. Joint Forces Command, and based on 600,000 documents captured in post-Saddam Iraq, found that Iraq during the early to mid-1990s actively supported Egyptian Islamic Jihad, which in 1998 formally merged with Al Qaeda, but that the documents do not reveal "direct coordination and assistance between Saddam Hussein's regime and Al Qaeda." Some of the intelligence information that the Bush Administration relied on to judge linkages between Iraq and Al Qaeda was publicized not only in Secretary of State Powell's February 5, 2003, briefing to the U.N. Security Council, but also, and in more detail, in an article in The Weekly Standard . Vice President Cheney has been quoted as saying the article represents the "best source of [open] information" on the issue. The article contains excerpts from a memorandum, dated October 27, 2003, from Undersecretary of Defense for Policy Douglas Feith to Senators Pat Roberts and Jay Rockefeller, the then chairman and vice chairman of the Senate Intelligence Committee. The memorandum reportedly was based on research and analysis of intelligence and other information by the "Office of Special Plans," an Iraq policy planning unit within the Department of Defense set up in early 2002 but disbanded in the fall of 2002. The following sections analyze details of the major themes in the Administration argument. The "DOD memorandum," as well as other accounts, include assertions that Iraqi intelligence developed a relationship with Al Qaeda in the early 1990s, brokered by the Islamist leaders of Sudan. At the time, Osama bin Laden was in Sudan. He remained there until Sudan expelled him in mid-1996, after which he went to Afghanistan. According to the purported memo, the Iraq-Al Qaeda relationship included an agreement by Al Qaeda not to seek to undermine Saddam's regime, and for Iraq to provide Al Qaeda with conventional weapons and WMD. The Administration view is that Iraq was highly isolated in the Arab world in the early 1990s, just after its invasion of Kuwait in August 1990, and that it might have sought a relationship with Al Qaeda as a means of gaining leverage over the United States and a common enemy, the regime of Saudi Arabia. From this perspective, the relationship served the interests of both, even though Saddam was a secular leader while Al Qaeda sought to replace regional secular leaders with Islamic states. The purported DOD memorandum includes names and approximate dates on which Iraqi intelligence officers visited bin Laden's camp outside Khartoum and discussions of cooperation in manufacturing explosive devices. It reportedly discusses subsequent meetings between Iraqi intelligence officers and bin Laden and his aides in Afghanistan and Pakistan, continuing until at least the late 1990s. The memorandum cites intelligence reports that Al Qaeda operatives were instructed to travel to Iraq to obtain training in the making and deployment of chemical weapons. Secretary of State Powell, in his February 5, 2003, U.N. briefing, citing an Al Qaeda operative captured in Afghanistan, stated that Iraq had received Al Qaeda operatives "several times between 1997 and 2000 for help in acquiring poison gases."