In the Iraq disarmament crisis of the early 2000s, Iraq, led by president Saddam Hussein, was pressured by the United States and its other adversaries to destroy alleged stockpiles of weapons of mass destruction (WMD)—biological, chemical, and nuclear. In the 1980s, Iraq had programs to produce all three, but in the 1990s, the programs were ended, and the WMD were destroyed. The U.S.' rationale for its 2003 invasion of Iraq was that the country still had WMD, and would use them.

In 1998, the U.S. officially declared its support for regime change in Iraq. Soon after al-Qaeda's September 11, 2001 attacks (9/11), U.S. president George W. Bush declared America's global "war on terror". Five Americans then died in anthrax attacks; the perpetrator is unconfirmed, but U.S. officials publicly speculated it was Iraq. Bush and his administration, spurred by members Dick Cheney and Donald Rumsfeld, alleged in 2002 that Iraq was sponsoring terrorism, linked to al-Qaeda, and had ongoing WMD programs; American officials cited Iraq buying aluminum tubes and documents alleging Iraq wanted uranium as proof of a nuclear weapons program. The U.S. threatened to invade Iraq if the alleged WMD were not destroyed, and their programs not ended. In November 2002, Saddam agreed to let United Nations (UN) inspectors search Iraq for WMD. The weapons were not found, and the U.S. then claimed they were still hidden.

The U.S. wanted international military backing for an invasion, but other countries, including fellow UN Security Council (UNSC) members, were unsupportive, citing no evidence for WMD. In February 2003, U.S. official Colin Powell spoke to the UNSC, alleging that Iraq had hid WMD before inspections, and could use WMD on American cities. Citing an Iraqi defector, Powell also claimed Iraq had mobile weapons facilities. Subsequently, the invasion received increased international support. A U.S.-led international coalition invaded Iraq in March, beginning the Iraq War (2003–2011). During the war, WMD were still not found, and Powell and Bush admitted in 2004 that they did not exist; Powell claimed the U.S. suffered an "intelligence failure", and he resigned from office. Throughout 2003, the uranium documents were found to be forged, and in 2011, the defector admitted to lying.

Iraq and weapons of mass destruction

The Iraqi government started research on nuclear technology in 1956, when they received a research reactor (a nuclear reactor meant for research purposes) from the Soviet Union, and founded the Iraqi Atomic Energy Commission to study nuclear power. The Nuclear Threat Initiative writes that "these early activities were likely driven by peaceful intentions", to promote nuclear power following the U.S. government's "Atoms for Peace" initiative.

An international ban on distributing nuclear technology was first promoted in the United Nations by Ireland in 1961. In 1970, the Non-Proliferation Treaty (NPT), the first binding commitment by the international community to promote nuclear disarmament amongst nuclear weapon-equipped states, came into effect; at that point, the nuclear states were China, France, the United Kingdom, the United States, and the Soviet Union. Iraq signed the treaty in 1969. In 1975, the Biological Weapons Convention (BWC) treaty came into effect, internationally banning the creation of biological weapons: pathogens or toxins ("biological agents") like anthrax and ricin that are delivered in a weaponized manner, such as inside of missiles and grenades. Iraq signed the treaty in 1972. In the early 1970s, while Saddam Hussein was Iraq's vice president, and its de facto ruler, the country began a nuclear weapons program, immediately violating the NPT. At the Tuwaitha Nuclear Research Center in Baghdad, Iraq installed two research reactors from France in 1976, and in 1979, installed two facilities acquired from an Italian company: one to manufacture nuclear fuel to run the nuclear power station, and one to separate plutonium and then handle it using a "hot cell" chamber. In 1975, Saddam stated that their purchase of a research reactor from France represented "the first Arab attempt at nuclear arming".

Presidency of Saddam Hussein

Saddam, a Sunni Arab, was the president of Iraq from 1979 to 2003. His government violently oppressed Iraqi Shia Arabs, who mostly live in the country's south, as well as the Iraqi Kurds, non-Arab Sunnis in the northern Iraqi Kurdistan region. The center of Iraq, which includes the capital Baghdad and the major cities of Fallujah and Tikrit, mostly contains Sunni Arabs. and is called the "Sunni Triangle". Saddam intentionally filled with his government with Sunni Arabs, creating a base of support for him in the triangle, so while the area only made up 15% to 20% of Iraq's population as of October 2003, it cemented his ability to opress his opposition.

Iran–Iraq War

In 1980, Iraq invaded neighboring Iran, beginning the Iran–Iraq War. Saudi Arabia, Kuwait, and other Gulf Arab states financed Iraq's war effort, while France and the Soviet Union sold weapons to Iraq. The U.S. generally and openly supported Iraq, but secretly sold weapons to Iran to deal with a hostage crisis in Lebanon, and fund the Nicaraguan Contras. Iran was also supported by Libya and Syria. The war ended in a ceasefire in 1988, after major losses on both sides.

Paul Wolfowitz, the military analyst for the U.S. Department of Defense (DOD) under president Ronald Reagan, formulated a policy with regard to Iraq and other "potential aggressor states", dismissing "containment" in favor of "preemption", with the goal of striking first to eliminate threats. This policy was short-lived, however, and president Bill Clinton, along with George H. W. Bush, Colin Powell, and other former Bush administration officials, dismissed calls for preemption in favor of continued containment. This was the policy of George W. Bush as well for his first several months in office.

Gulf War In 1990, a diplomatic crisis occurred in which Saddam accused Kuwait, Iraq's neighbor, of stealing Iraqi oil. On 2 August, Iraq began an invasion of Kuwait, which began the Gulf War. Kuwait's allies, included the U.S., built up troops over the following months, and in 1991, began an air campaign and land invasion of Kuwait that forced the Iraqi military to retreat across the Iraq–Kuwait border.

After the Gulf War Following the Gulf War, the Iraqi Army was reduced to 23 divisions with a total of about 375,000 troops. The Iraqi Air Force was reduced to less than 300 aircraft. The Iraqi Navy was almost completely destroyed, and its few remaining operational vessels were in a poor state of repair, limiting their capabilities to that of limited mining and raiding missions. Any rebuilding that was done went into the Republican Guard, and the formation of the Special Republican Guard.

In the decade after the Gulf War, the United Nations Security Counsel (UNSC) passed sixteen resolutions calling for the complete elimination of Iraqi weapons of mass destruction. Member states communicated their frustration over the years that Iraq was impeding the work of the UN Special Commission and failing to take seriously its disarmament obligations. Iraqi security forces had on several occasions physically prevented weapons inspectors from doing their job and in at least one case, took documents from them.

U.S. support for regime change in Iraq

On 29 September 1998, the U.S. Congress passed the Iraq Liberation Act supporting the efforts of Iraqi opposition groups to remove Saddam from office. The Act was signed by Clinton on 31 October 1998. That same day, Iraq announced it would no longer cooperate with UN weapons inspectors.

The UN, under Kofi Annan, brokered a deal wherein Iraq would allow weapons inspectors back into the country. Iraq ceased cooperating with inspectors only days later. The inspectors left the country in December. Inspectors returned the following year as part of the UN Monitoring, Verification and Inspection Commission (UNMOVIC).

Presidency of George W. Bush

George W. Bush was inaugurated as U.S. president on 20 January 2001. His vice president was Dick Cheney. Multiple outlets write that Cheney had the most powerful and influential U.S. vice presidency in history. Before he took office, he had been Secretary of Defense under George H. W. Bush, as well as the CEO of Halliburton, an oil and engineering company with an extensive list of U.S. military contracts; he still had financial ties to the company while in office. Initially, George W. Bush's Secretary of State was Colin Powell, and his Secretary of Defense was Donald Rumsfeld.

Crisis (2001–2003)

2001

11 September attacks

On 11 September 2001 (9/11), the Islamic extremist group al-Qaeda, led by Osama bin Laden, enacted coordinated terrorist attacks against the U.S. 19 members of al-Qaeda hijacked four American commercial airliners in an attempt to crash them into national landmarks. Two were crashed into the World Trade Center in New York City, causing it to collapse. American Airlines Flight 77 was crashed into the DOD's headquarters, the Pentagon in Virginia. United Airlines Flight 93 crashed in a field in Pennsylvania; while the hijackers had intended to attack Washington, D.C., the other passengers and crew attempted to take back the plane's cockpit back from the hijackers, causing the crash. The four attacks directly killed at least 2,996 people, including all of the hijackers. An estimated 25,000 people were injured.

At 9:52 a.m. EST, 15 minutes after the Flight 77 crash, the National Security Agency (NSA) intercepted a phone call from a deputy of bin Laden in Afghanistan to someone in the Republic of Georgia. The deputy said he had "heard good news", and that another target would soon be attacked. Flight 93's crash followed this, at 10:03. Donald Rumsfeld was told about the call at 12:05 p.m., and within hours, he was told that U.S. intelligence had looked up the flight manifests of the hijacked planes, and found three members linked to al-Qaeda—one to al-Qaeda's USS Cole bombing in 2000 that killed U.S. Navy sailors. At 2:40 p.m., as Rumsfeld was in the National Military Command Center at the Pentagon, he ordered the military to attack Iraq; aides that were near him said later that he did not have evidence for Iraq being involved in the attacks. The aides took notes that quoted Rumsfeld as saying: "Go massive. Sweep it all up. Things related and not". One message he sent to military commanders wrote: "Best info fast. Judge whether good enough hit S.H. [Saddam Hussein] at same time. Not only UBL. [Usama bin Laden]". The attack on Iraq ultimately did not happen, while Rumsfeld's order remained a secret for a year.

Throughout the day, Bush was also told about the phone call and the manifest names. That night, he stated in a speech to the American public:"The search is underway for those who are behind these evil acts. ... We will make no distinction between the terrorists who committed these acts, and those who harbor them."

Before retiring to bed, he wrote in his diary that "we think it's Osama bin Laden."

Aftermath of 9/11

In the following days, U.S. officials threatened the Taliban government of Afghanistan to give up bin Laden, whom they were harboring, or else face military action. Cheney stated: "if you provided sanctuary to terrorists, you face the full wrath of the United States". On 16 September, Bush stated that the perpetrators of 9/11 "have declared war on America", and that the U.S. was now fighting a "war on terrorism". Dick Cheney, using his unique influence, became a main architect of what has since been named America's "war on terror". 9/11 brought to life Wolfowitz's and other "hawks'" advocacy for preemptive action; Iraq was widely agreed to be a likely subject of this new policy. Powell continued to support the philosophy behind containment.