http://victoria.indymedia.org/news/2004/06/27004.php According to the NYT's article concerning the hunt for those weapons :
"Though the White House officially blessed the outlines of the mission about eight weeks ago, planning for the hunt began at the Pentagon last July, officials said.
In August 2002, the Pentagon operated National Defense University in Washington held a secret meeting to consider how best to go about disarming Iraq. In September 2002, former inspectors of the old Unscom met with officials from several Pentagon offices, including the Central Command in Tampa, Fla., to discuss the lessons learned from the inspectors' eight year effort to disarm Iraq of unconventional weapons." (end quote NYT)
After months of relatively fruitless international inspections, the discovery of such arms is 'an absolute must', officials said, 'because how can we otherwise vindicate the US administration's decision, to go to war to disarm Iraq, if indeed nothing is 'found' ?
The US government can not, and will not take that risk.