It is of course quite possible that the Powers That Be were fully informed of the fact that Iraq did not possess any chemical weapons, and that therefore, issuing the troops with suits, masks, and other countermeasures against such a potential threat was unnecessary.
Now why was it that "we" went into Iraq again? Oh yes, it was 9/11, wasn't it.
Oh no, hang on, that was Afghanistan and the Taliban and Osama bin B@stard.
Iraq was about....um....well, it couldn't have been the switch from the US dollar to the Euro as the currency for oil transactions, back in October 2000, now could it. That would smack of conspiracy theory.