Well, then Iraqis have been simply superb at moving away the WMD in all the stealthiness - avoiding the western air & space recon equiptment.
They surely can stealthily hide all the WMD, but not some small mass graves, which has required less effort than hiding WMD.
So.. all the intelligence advantages the western powers posesses, had this hide-the-WMD operation go unnoticed.
Even from the civils.
All these ex-iraqi officials have given up information to the coalition forces, but not a single lousy guard has turned up and said "I know a plant which had a WMD storage, but they moved it out from there..."
Actually.. it is interesting how byrocrats knew more about WMD than their own intelligence services!