When then-Secretary of State Colin Powell made the US case for the invasion of Iraq at the United Nations Security Council on February 3, 2003, he cited evidence that Saddam Hussein continued to develop weapons of mass destruction.
"We have firsthand descriptions of biological weapons factories on wheels and on rails," Powell said. "In a matter of months, they can produce a quantity of biological poison equal to the entire amount that Iraq claimed to have produced in the years prior to the Gulf War."
Powell said this was one of the "most worrisome things that emerges from the thick intelligence file we have on Iraq."
The claim helped justify the US-led invasion of Iraq. It also turned out to be false, and was just one piece of questionable intelligence pushed on the White House and US spy agencies in the run-up to the Iraq invasion by an organization headed by a man who had long lobbied for the United States to topple Saddam Hussein: Ahmed Chalabi.
Chalabi died Tuesday, at the age of 71, at his Baghdad home, reportedly from a heart attack.
Chalabi founded the Iraqi exile opposition group, the Iraqi National Congress, that eventually connected intelligence agencies with at least one source of the false biological weapons claims that appeared in Powell's speech.
After the invasion, in a 2004 interview with London's Telegraph newspaper, Chalabi "shrugged off charges" that he deliberately misled the US government.
"We are heroes in error," he told the paper. "As far as we're concerned we've been entirely successful. That tyrant Saddam is gone and the Americans are in Baghdad. What was said before is not important."
Shortly after he made the comments, he was accused of providing Iran with information about US operations in Iraq. US and Iraqi forces raided his offices in Baghdad in 2004, though charges were never brought.
It was a spectacular fall from grace for a man who the US government had once considered as a possible post-Saddam leader of Iraq. He was among the Iraqi exiles appointed to the Iraqi Governing Council that nominally managed the country's transition from invasion to elections in 2004, with frequent interference from the US.
Chalabi was also a major proponent of "de-Baathification," one of the most disastrous policies employed by the US after the invasion. De-Baathification referred to the removal of anyone who was a member of Hussein's ruling Baath Party from public life, including low-level functionaries who were obliged to join the party simply in order to secure a job. The policy created a ready base of support for the Sunni insurgency that killed thousands of Iraqis and American soldiers, and formed the seed of the insurgency that continues to fight the Iraqi government today. The program also dissolved the Iraqi army, a move that disenfranchised hundreds of thousands of people, many of whom had left the battlefield with their weapons when the government fell.
Chalabi's personal history was closely linked to that of Iraq's. Chalabi's family counted themselves among Iraq's elite until the revolution in 1958 that deposed Iraq's monarchy and brought a socialist government to power, sending them into exile. Chalabi was 13 and would not return to Baghdad until 2003. In the interim, he studied in the US at the MIT and the University of Chicago, where he received a doctorate in mathematics.
In 1992 Chalabi and other exiles founded the Iraqi National Congress, a group dedicated to overthrowing Saddam Hussein. The group became a CIA asset in the mid-1990s as it carried out at least two bombings in Baghdad and launched an abortive invasion of northern Iraq in 1995.
Throughout the 1990s and up until the invasion in 2003, Chalabi cultivated relationships with journalists and politicians, particularly in the US. In making the case for war, the INC lobbied publicly while also supplying sources who asserted that Saddam Hussein possessed weapons of mass destruction to the CIA and Pentagon. The INC also fed information about what it said was Saddam's weapons programs and failure to comply with a United Nations-backed disarmament program put in place after Iraq's invasion of Kuwait in 1991.
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Though Chalabi was a recognizable face to the international community, he and many of the other exiles who expected to become Iraq's new rulers had little name recognition or trust amongst average Iraqis who had suffered under Hussein while Chalabi lived a lavish life abroad. Chalabi himself had been convicted in absentia of stealing millions from a bank he founded in Jordan, Petra Bank, and was often derided by average Iraqis as someone who rode in on the back of an American tank. His political party failed to win a single seat in the 2005 Iraqi parliamentary elections.
But Chalabi was a savvy political survivor, and he eventually acknowledged his lack of grassroots support by allying himself with the Sadr Movement, a populist Shiite party with a clerical leadership. He eventually won a seat in parliament, and was the head of the finance committee at the time of his death.
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Watch the VICE News documentary "Rearming Iraq: The New Arms Race."