The United Nations Monitoring, Verification and Inspection Commission (UNMOVIC) and the United States-led Iraq Survey Group (ISG) failed to find any of the alleged stockpiles of weapons of mass destruction in Iraq that were used as a rationale for the 2003 U.S.-led invasion. The United States effectively ended the search effort for unconventional weaponry in 2005, and the Iraq Intelligence Commission concluded that the judgements of the U.S. intelligence community regarding the continued existence of weapons of mass destruction and an associated military program were mistaken. The official findings of the CIA in 2004 were that Iraqi President Saddam Hussein "did not possess stockpiles of illicit weapons at the time of the U.S. invasion in March 2003 and had not begun any program to produce them."

During and immediately following these searches, many theories were proposed to explain the sudden disappearance of Iraqi WMD—assuming that any had, in fact, existed. These theories included conspiracy theories, accusations against other governments and claims of successful deception efforts by Saddam Hussein. In various theories, Russia, Syria, Lebanon, Iran, and Pakistan were all alleged to be involved with moving or concealing Iraq's supposed WMD arsenal. In 2004, a theory was advanced that WMD might still remain hidden somewhere within Iraq.Tweedie, Neil. Report holds out the possibility that WMD may still be found ... one day The Daily Telegraph. July 14, 2004. While some remnant chemical warheads were discovered, dating to the Iran–Iraq War era, none were newer than 1991. Some of these chemical weapons were found near the Muthanna State Establishment facility northwest of Baghdad.

After much criticism of the war during the years that followed, every figure who had previously supported the claims of WMD in Iraq, with the exception of U.S. Vice President Dick Cheney, acknowledged that they had been wrong.At Least Trump Got One Thing Right. There Were No WMD in Iraq , Huffington Post, "But the very leaders who sold them the goods on Iraq’s non-existent weapons program have (with the exception of Cheney) come out and acknowledged that there were no WMDs." "In his memoir, Known and Unknown, Rumsfeld specifically mentioned the lack of WMD stockpiles in Iraq and said “Saddam Hussein didn’t have ready stockpiles of WMD our intelligence community believed we would uncover. The shift in emphasis suggested that Iraq’s intentions and capability for building WMD had somehow not been threatening. Many Americans and others around the world accordingly came to believe the war was unnecessary.” "National Security Advisor Condoleezza Rice similarly acknowledged, “What we have is evidence that there are differences between what we knew going in and what we found on the ground.”" "Secretary of State Colin Powell would also state, “Of course I regret that a lot of it [the evidence] turned out be wrong.”" A related debate also emerged over whether the figures who had pushed for war were inadvertently misled by intelligence or had, in fact, intentionally deceived the public.Dick Cheney's Biggest Lie , Newsweek The failure to find WMD "would leave deep and lasting consequences for both spies and politicians," and did "lasting damage to the credibility of U.S. intelligence." It also spurred the U.S. intelligence community to develop "new standards for analysis and oversight." Avril Haines, U.S. Director of National Intelligence from 2021 to 2025, was quoted in a 2023 article as saying: “We learned critical lessons in the wake of our flawed assessment of an active WMD program in Iraq in 2002," having "expanded the use of structured analytic techniques, established community-wide analytic standards, and enhanced tradecraft oversight" in the time since.

No such stockpiles Saddam knew there were no stockpiles On 13 December 2003, Saddam Hussein was captured by U.S. forces during Operation Red Dawn. Time Online Edition reports that in his first interrogation he was asked whether Iraq had any WMD. According to an official, his reply was:

"No, of course not, the U.S. dreamed them up itself to have a reason to go to war with us." The interrogator continued along this line, said the official, asking: "if you had no weapons of mass destruction then why not let the U.N. inspectors into your facilities?" Saddam’s reply: "We didn’t want them to go into the presidential areas and intrude on our privacy."Notes from Saddam in custody Time. December 14, 2003. Later, through interrogations in US custody, Saddam revealed that, immediately prior to the start of the 2003 US invasion, he had announced to his generals that there were no WMD. One theory given currency by Charles Duelfer is that Saddam sent out different signals to different people in order to keep them confused and help stay in power.Facing defeat, Saddam clung to his fantasies The Observer October 10, 2004. Documents since captured inside Iraq by coalition forces are reported to reveal Saddam's frustration with weapon inspections. Meeting transcripts record him saying to senior aides: "We don't have anything hidden!" In another, he remarks: "When is this going to end?" And another: "Don't think for a minute that we still have WMD. We have nothing."Transcripts Show Saddam Frustrated Over WMD Claims Fox News March 22, 2006.

Hans Blix from the Weapons of Mass Destruction Commission said in his early 2004 book, Disarming Iraq, that Saddam had successfully been deterred from keeping WMD stockpiles by outside pressure. In regards to why he appeared so unsuccessful in convincing others that Iraq had no stockpiles (allowing for sanctions that crippled Iraq's economy), Blix pointed out several reasons: The United States had repeatedly made it clear to Saddam that only him disappearing from the stage would solve the issue. He did not expect the inspectors to go away. Saddam was often noted as being very proud of his country, and may have been against allowing other countries' observers to just enter several of Iraq's most important facilities. Iraq did repeatedly tell the UN that it had followed their obligations and that they had eliminated all prohibited weapons, but they might have considered deliberate ambiguity to be advantageous. Iraq may have wanted to keep their conventional weaponry secret. Some inspectors had close connections with the military and intelligence of countries that were bombing Iraq.

Saddam did not know there were no stockpiles According to The Guardian in late 2003, British officials in Whitehall began circulating a theory that Saddam Hussein and his senior advisers "may have been hoodwinked" by lower-ranking officers "into believing that Iraq really did possess weapons of mass destruction." And as most of the informers for British intelligence were the same high-level advisers close to Saddam, the British were also fooled. The paper adds that this hypothesis "is open to the interpretation that the government is searching for an excuse, however implausible, for failure to discover any WMD in Iraq."New theory for Iraq's missing WMD The Guardian December 24, 2003. Commenting on the findings of the Butler intelligence review six months later, USA Today reported that Britain's Secret Intelligence Service had "shockingly few reliable human sources inside Saddam's regime."U.S., British probes reach similar findings USA Today July 14, 2004.

Stockpiles transported to another country Rumors abounded of possible transportation of Iraqi weapons of mass destruction to foreign countries, namely Syria, Lebanon and Iran. This was particularly prevalent in the weeks before Operation Iraqi Freedom began.

Possibility of Russian involvement

Romanian intelligence defector Ion Mihai Pacepa alleged that an operation for the removal of chemical weapons was prepared by the Soviet Union for Libya, and that he was told over thirty years ago by Romanian President Nicolae Ceaușescu, KGB chairman Yury Andropov, and later, Yevgeny Primakov, about the existence of a similar plan for Iraq. It is "perfectly obvious", wrote Pacepa, that the Russian GRU agency helped Saddam Hussein to destroy, hide, or transfer his chemical weapons prior to the American invasion of Iraq in 2003. "After all, Russia helped Saddam get his hands on them in the first place.""Operation Sarindar" (meaning "emergency exit") was an operating procedure designed by Soviet military intelligence to get rid of all traces of chemical weapons delivered or produced under Soviet guidance in Third World countries "if the Western imperialists ever got near them", writes Pacepa. Pacepa, Ion. Ex-spy fingers Russians on WMD , The Washington Times, October 2, 2003.

Syria

Former Iraqi general Georges Sada claimed that in late 2002, Saddam had ordered all of his stockpiles to be moved to Syria. He appeared on Fox News' Hannity & Colmes in January 2006 to discuss his book, Saddam's Secrets: How an Iraqi General Defied and Survived Saddam Hussein. Anticipating the arrival of weapon inspectors on November 1, Sada said Saddam took advantage of the June 4 Zeyzoun Dam disaster in Syria by forming an "air bridge", loading them onto cargo aircraft and flying them out of the country.

They were moved by air and by ground, 56 sorties by jumbo, 747, and 27 were moved, after they were converted to cargo aircraft, they were moved to Syria.Former Top Military Aide to Saddam Reveals Dictator's Secret Plans January 26, 2006.

In January 2004, Nizar Nayuf, a Syrian journalist who moved to Western Europe, said in a letter to the Dutch newspaper De Telegraaf that he knows the three sites where Iraq's weapons of mass destruction are kept inside Syria. According to Nayuf's witness, described as a senior source inside Syrian military intelligence he had known for two years,Syria Role On Iraqi Arms Is Studied Washington Post January 10, 2004. Iraq's WMD are in tunnels dug under the town of al-Baida near the city of Hama in northern Syria, in the village of Tal Snan, north of the town of Salamija, where there is a big Syrian air force camp, and in the city of Sjinsjar on the Syrian border with the Lebanon, south of Homs city. Nayouf also wrote that the transfer of Iraqi WMD to Syria was organized by the commanders of Saddam Hussein's Iraqi Republican Guard, including General Shalish, with the help of Assef Shawkat, Bashar al-Assad's cousin. Shoakat is the CEO of Bhaha, an import/export company owned by the Assad family.A senior Syrian journalist reports Iraq WMD located in three Syrian sites 2LA.org January 2004. U.S. Secretary of State Condoleezza Rice responded to this accusation by saying "I don't think we are at the point that we can make a judgment on this issue. There hasn't been any hard evidence that such a thing happened. But obviously we're going to follow up every lead, and it would be a serious problem if that, in fact, did happen."

A similar claim was made by Lieutenant General Moshe Ya'alon, a former Israeli officer who served as chief of staff of the Israel Defense Forces from July 2002 to June 2005. In April 2004, he was quoted as saying that "perhaps they transferred them to another country, such as Syria."Israeli military chief says Iraq had chemical weapons The Sydney Morning Herald April 27, 2004. General Ya'alon told the New York Sun more firmly in December 2005 that "He [Saddam] transferred the chemical agents from Iraq to Syria."Saddam's WMD Moved to Syria, An Israeli Says New York Sun December 15, 2005. The Fall 2005 Middle East Quarterly also reported Israeli Prime Minister Ariel Sharon as having said in a December, 2002 appearance on Israel's Channel 2, "... chemical and biological weapons which Saddam is endeavoring to conceal have been moved from Iraq to Syria."The Middle East Quarterly Fall 2005.

In February 2006, Ali Ibrahim al-Tikriti, a former Iraqi general who defected shortly before the Gulf War in 1991, gave an interview to Ryan Mauro, in which he stated: