The lead-up to the Iraq War began with United Nations Security Council Resolution 687 and subsequent UN weapons inspectors inside Iraq. This period also saw low-level hostilities between Iraq and the United States-led coalition from 1991–2003.
The rationale for the Iraq War has been a controversial issue since the Bush Administration began actively pressing for military intervention in Iraq in late 2001. The primary rationalization for the Iraq War was articulated by a joint resolution of the United States Congress known as the Iraq Resolution.

The 2003 State of the Union Address was given by the 43rd President of the United States, George W. Bush, on Tuesday, January 28, 2003, at 9 p.m. EST, in the chamber of the United States House of Representatives to the 108th United States Congress. It was Bush's second State of the Union Address and his third speech to a joint session of the United States Congress. Presiding over this joint session was the House Speaker, Dennis Hastert, accompanied by Dick Cheney, the Vice President of the United States.

The Authorization for Use of Military Force Against Iraq Resolution of 2002, informally known as the Iraq Resolution, is a joint resolution passed by the United States Congress in October 2002 as Public Law No. 107-243, authorizing the use of the United States Armed Forces against Saddam Hussein's Iraq government in what would be known as Operation Iraqi Freedom.

The Authorization for Use of Military Force (AUMF) is a joint resolution of the United States Congress which became law on September 18, 2001, authorizing the use of the United States Armed Forces against those responsible for the September 11 attacks. The authorization granted the President the authority to use all "necessary and appropriate force" against those whom he determined "planned, authorized, committed or aided" the September 11 attacks, or who harbored said persons or groups. The AUMF was passed by the 107th Congress on September 14, 2001, and signed into law by President George W. Bush on September 18, 2001. In December 2016, the Office of the President published a brief interpreting the AUMF as providing Congressional authorization for the use of force against al-Qaeda and other militant groups.

The Bush–Aznar memo is reportedly a documentation of a February 22, 2003 conversation in Crawford, Texas between US president George W. Bush, Prime Minister of Spain José María Aznar, National Security Advisor Condoleezza Rice, Daniel Fried, Alberto Carnero, and Javier Rupérez, the Spanish ambassador to the U.S. British Prime Minister Tony Blair and Italian Prime Minister Berlusconi participated by telephone. Rupérez transcribed the meeting's details which El País, a Madrid daily newspaper, published on September 26, 2007. The conversation focuses on the efforts of the US, UK, and Spain to get a second resolution passed by the United Nations Security Council. This "second resolution" would have followed Resolution 1441. Supporters of the resolution also referred to it as the "eighteenth resolution" in reference to the 17 UN resolutions that Iraq had failed to comply with.

The Bush–Blair 2003 Iraq memo or Manning memo is a secret memo of a two-hour meeting between American President George W. Bush and British Prime Minister Tony Blair that took place on 31 January 2003 at the White House. The memo purportedly shows at that point, the administrations of Bush and Blair had already decided on the invasion of Iraq two months later. The memo was written by Blair's chief foreign policy adviser, David Manning, who participated in the meeting.

Doe v. Bush, 323 F.3d 133, was a court case challenging the constitutionality of the 2003 invasion of Iraq. The case was dismissed, since the plaintiffs failed "to raise a sufficiently clear constitutional issue." The Authorization for Use of Military Force Against Iraq Resolution of 2002 was challenged by "a coalition of U.S. soldiers, parents of U.S. soldiers, and members of Congress" prior to the invasion to stop it from happening. They claimed that an invasion of Iraq would be illegal. Judge Lynch wrote of their argument, "They base this argument on two theories. They argue that Congress and the President are in collision -- that the President is about to act in violation of the October Resolution. They also argue that Congress and the President are in collusion -- that Congress has handed over to the President its exclusive power to declare war."

Tahir Jalil Habbush al Takriti is a former Iraqi intelligence official who served under the regime of Saddam Hussein; in 2001, he was Iraq's head of intelligence and as such, informed MI6 in January 2003 that Iraq had no WMD. He was the Jack of Diamonds in the most-wanted Iraqi playing cards and is still a fugitive with up to $1 million reward for information leading to his capture.

Iraq's era under President Saddam Hussein was notorious for its severe violations of human rights, which were perceived to be among the worst in the world. Secret police, state terrorism, torture, mass murder, genocide, ethnic cleansing, rape, deportations, extrajudicial killings, forced disappearances, assassinations, chemical warfare, and the destruction of southern Iraq's marshes were some of the methods Saddam and the country's Ba'athist government used to maintain control. The total number of deaths related to torture and murder during this period is unknown, but estimated to be around 250,000 according to Human Rights Watch, with the great majority of those occurring as a result of the 1988 Anfal genocide and the suppression of the 1991 uprisings in Iraq. Human Rights Watch and Amnesty International issued regular reports of widespread imprisonment and torture.

The sanctions against Iraq were a near-total financial and trade embargo imposed by the United Nations Security Council on Ba'athist Iraq. They began August 6, 1990, four days after Iraq's invasion of Kuwait, stayed largely in force until May 22, 2003, and persisted in part, including reparations to Kuwait, through the present. The original stated purposes of the sanctions were to compel Iraq to withdraw from Kuwait, to pay reparations, and to disclose and eliminate any weapons of mass destruction.

Aluminum tubes purchased by the nation of Iraq were intercepted in Jordan in 2001. In September 2002 they were publicly cited by the White House as evidence that Iraq was actively pursuing an atomic weapon. Prior to the 2003 invasion of Iraq, many questioned the validity of the claim. After the invasion, the Iraq Survey Group determined that the best explanation for the tubes' use was to produce conventional 81-mm rockets; no evidence was found of a program to design or develop an 81-mm aluminum rotor uranium centrifuge.
The Iraqi Perspectives Project is a research effort conducted by United States Joint Forces Command, focusing on Operation Iraqi Freedom.

The Land letter was a letter sent to U.S. President George W. Bush by five evangelical Christian leaders on October 3, 2002, outlining their support for a just war pre-emptive invasion of Iraq. As its foundation for support, the letter refers to the "criteria of just war theory as developed by Christian theologians in the late fourth and early fifth centuries A.D." The letter was written by Richard D. Land, president of the Ethics & Religious Liberty Commission of the Southern Baptist Convention. It was co-signed by:Chuck Colson, founder of Prison Fellowship Ministries Bill Bright, chairman of the Christian organization Cru James Kennedy, president of Coral Ridge Ministries, and Carl D. Herbster, president of the American Association of Christian Schools

The United Nations Security Council (UNSC) is the organ of the United Nations charged with maintaining peace and security among nations. While other organs of the United Nations only make recommendations to member governments, the Security Council has the power to make decisions which member governments are obliged to carry out under the United Nations Charter. The decisions of the Council are known as United Nations Security Council Resolutions.

Mobile weapons laboratories are bioreactors and other processing equipment to manufacture and process biological weapons that can be moved from location to location either by train or vehicle. No such labs have ever been proven to exist.

The Pentagon military analyst program was a propaganda campaign of the U.S. Department of Defense (DoD) that was launched in early 2002 by then-Assistant Secretary of Defense for Public Affairs Victoria Clarke. The goal of the operation is "to spread the administrations's talking points on Iraq by briefing retired commanders for network and cable television appearances," where they have been presented as independent analysts; A Pentagon spokesman said the Pentagon's intent is to keep the American people informed about the so-called War on Terrorism by providing prominent military analysts with factual information and frequent, direct access to key military officials. The Times article suggests that the analysts had undisclosed financial conflicts of interest and were given special access as a reward for promoting the administration's point of view. On 28 April 2008, the Pentagon ended the operation. A DoD Inspector General investigation found no wrongdoing on the part of the DoD.

William Lewis Safir, better known as William Safire, was an American author, columnist, journalist, and presidential speechwriter.

The Senate Report on Iraqi WMD Intelligence was the report by the United States Senate Select Committee on Intelligence concerning the U.S. intelligence community's assessments of Iraq during the time leading up to the 2003 invasion of Iraq. The report, which was released on July 9, 2004, identified numerous failures in the intelligence-gathering and -analysis process. The report found that these failures led to the creation of inaccurate materials that misled both government policy makers and the American public.

In March 2003 the United States government announced that "diplomacy has failed" and that it would proceed with a "coalition of the willing" to rid Iraq under Saddam Hussein of weapons of mass destruction the US and UK insisted it possessed. The 2003 invasion of Iraq began a few days later.

United Nations Security Council Resolution 1441 is a United Nations Security Council resolution adopted unanimously by the United Nations Security Council on 8 November 2002, offering Iraq under Saddam Hussein "a final opportunity to comply with its disarmament obligations" that had been set out in several previous resolutions. It provided a justification for what was subsequently termed the US invasion of Iraq.

Iraq actively researched and later employed weapons of mass destruction (WMD) from 1962 to 1991, when it destroyed its chemical weapons stockpile and halted its biological and nuclear weapon programs as required by the United Nations Security Council. The fifth President of Iraq, Saddam Hussein, was internationally condemned for his use of chemical weapons during the 1980s campaign against Iranian and Kurdish civilians during and after the Iran–Iraq War. In the 1980s, Saddam pursued an extensive biological weapons program and a nuclear weapons program, though no nuclear bomb was built. After the Persian Gulf War (1990–1991), the United Nations located and destroyed large quantities of Iraqi chemical weapons and related equipment and materials; Iraq ceased its chemical, biological and nuclear programs.