Much of the position is summed up in the main article on the 2003 invasion of Iraq.
A summary of the United States government's case for military intervention in Iraq can be seen in the presentation that Secretary of State Colin Powell made to the UN Security Council on February 5, 2003. See The UN Security Council and the Iraq war for complete details. The US repeatedly claimed that they would shortly provide ample evidence of Iraqi deception, stating that it more than justified an invasion. UN weapons inspectors and several countries criticized the US's decision to hold on to evidence as long as it did. In late January, the US government announced that Colin Powell would meet with the UN to show them the newly unclassified evidence that US intelligence has collected. Powell's speech on February 5 showed that Iraq had made numerous efforts to obstruct the work of inspectors, and to develop and hide weapons of mass destruction. His speech also cited the quantities of chemical and biological weapons, and missiles, Iraq was known to possess in 1998 through UN inspections, most of which has not been accounted for and is simply missing. Powell's evidence included recorded phone coversations and satellite photos. However, much of Powell's evidence was largely circumstantial.
On April 2, 2004, Colin Powell "voiced new doubt yesterday on the administration's assertions of weapons of mass destruction in Iraq, saying the description in his U.N. presentation of mobile biological weapons laboratories appears to have been based on faulty sources". (Washington Post, April 3, 2004 ). In Iraq in May 2004 an 155-mmartillery shell was being used as an Improvised Explosive Device, the U.S. military said. The shell exploded, and two U.S. soldiers were treated for minor exposure to Mustard Gas, a nerve agent. In early November 2004 US marnies discovered seven weapons caches in Falluja, Iraq. One of those caches contained a suitcase full of vials labeled "Sarin" a deadly nerve agent.
Although president Bush has never said Saddam Hussein was linked to 9/11, there is evidence that Iraq had ties to Al Qaeda and other terrorist organizations before 9/11. Evidence about the Iraqi Intelligence Service and its ties with three leaders of the suicide hijacking plot: Mohammed Atta, Khalid al-Midhar, and Nawaf al-Hazmi includes a witness outside of Prague that saw al-Ani, the Iraqi agent, meeting with a young Arabic-looking male on April 8, 2001.
The U.S. cannot account for Atta's whereabouts on April 8, 2001. What is known, is that on April 4, 2001, Atta checked out of the Diplomat Inn in Virginia Beach. He was not seen again by any American witness for a week. In addition, whatever he was doing at that point — like, say, traveling overseas — must have required funding because, on April 4, he cashed a check for $8,000 from a SunTrust account, according to the FBI.
Czech intelligence conducted a search at the Iraqi embassy that found up al-Ani's appointment calendar. It indicated that the person he had a scheduled meeting with on that day was a "Hamburg student." As is by now well known, Atta led al Qaeda's Hamburg cell in Germany, and he was for a time enrolled as a student at Hamburg-Harburg Technical University.
February 24, 2004, CIA Director George Tenet stated in testimony before the Senate Intelligence Committee that the CIA had not discounted the Prague meeting. That concession was similar to Tenet's testimony on June 18, 2002, during which, regarding the Prague meeting, he stated that it was "possible that Atta traveled under an unknown alias since the US has been unable to establish that Atta left the US or entered Europe in April 2001 under his true name or any known aliases." The US now knows that al-Shibh (his al Qaeda Hamburg-cell associate) acquired false passports from a pair of Algerians named Khaled Madani and Moussa Laoua.
There is photographic and testimonial evidence of the existence in 2000, at Salmon Pak in Iraq, of a terrorist training camp that specialized in airline and other transportation targets. US Marines uncovered murals in Saddam's palaces in Iraq that depict the twin towers attack on 9/11.
The Senate considered Senate Concurrent Resolution 71, which urged President Clinton "to work with Congress in furthering a long-term policy aimed at definitively ending the threat to international peace and security posed by the government of Iraq and its weapons of mass destruction programs."
On October 31, 1998 Bill Clinton signed into law the Iraq Liberation Act which was passed by the US Congress by large bipartisan margins declaring: "It should be the policy of the United States to support efforts to remove the regime headed by Saddam Hussein from power in Iraq and to promote the emergence of a democratic government to replace that regime." The Act encouraged measures to support an Iraqi overthrow of Saddam, but prohibited the use of the U.S. military for such a purpose. The Act provides for funding and assistance to Iraqi opposition groups.
In early December of 1998, the British and US governments launched airstrikes against Iraq codenamed Operation Desert Fox. The US government urged UNSCOM executive chairman Richard Butler to withdraw, and "[a] few hours before the attack began, 125 UN personnel were hurriedly evacuated from Baghdad to Bahrain, including inspectors from the UN Special Commission on Iraq and the International Atomic Energy Agency."
US Senator Joseph Lieberman expressed strong support of the war. He was a "lead sponsor" of the Authorization for Use of Military Force Against Iraq.
Six House members, including Rep. John Conyers, D-Mich; Dennis Kucinich, D-Ohio; Jesse Jackson Jr., D-Ill.; Jim McDermott, D-Wash.; Jose Serrano, D-N.Y.; and Sheila Jackson Lee, D-Texas., members of the military and parents of servicemen asked a judge for an injunction barring the invasion of Iraq. The injunction hearing was held on February 20.
"The president is not a king," says John Bonifaz, the Boston lawyer who filed the lawsuit, "He does not have the power to wage war against another country absent a declaration of war from Congress."
Early on, several senior Republican leaders, including some within the Bush Administration, expressed reservations about an invasion of Iraq.
An investigative report published by Knight-Ridder in early October of 2002 showed that US intelligence analysts had serious misgivings about invading Iraq. The report showed that intelligence officials largely found no evidence to support the Bush administration's position that Saddam Hussein posed an immediate threat, but they were being squelched, while at the same time the intelligence community was being placed under intense pressure to find justification for Bush's position. This analysis seemed to be confirmed by the publication in The Times on May 1, 2005 of a leaked memo from Matthew Rycroft to British Ambassador to the United States David Manning, summarizing a July 23, 2002 meeting with Blair and other government officials "to discuss Iraq" The Downing Street Memo re Bush's Determination to Topple Saddam caused a political scandal in Britain and analysts identify it as a factor in Blair's reduced margin of victory in the elections which followed, but did not cause as much impact in the United States.