This must not be how Chalabi said it would work out: The bipartisan commission investigating the Sept. 11 terrorist attacks further called into question on Wednesday one of President Bush's rationales for the war with Iraq, and again put him on the defensive over an issue the White House was once confident would be a political plus. In questioning the extent of any ties between Iraq and Al Qaeda, the commission weakened the already spotty scorecard on Mr. Bush's justifications for sending the military to topple Saddam Hussein. Banned biological and chemical weapons: none yet found. Percentage of Iraqis who view American-led forces as liberators: 2, according to a poll commissioned last month by the Coalition Provisional Authority. Number of possible Al Qaeda associates known to have been in Iraq in recent years: one, Abu Musab al-Zarqawi, whose links to the terrorist group and Mr. Hussein's government remain sketchy.