"The weapons inspectors did disarm about 90% of their weapons (far more than the destruction by the Gulf war) until they had to leave in 1998.
And yet, the sanctions were not lifted."

Weapon inspectors are not weapon finders, they are verify Iraq's claims. Has any weapon inspector ever claimed that they were satified that all Iraq's weapons of mass destruction has been declared? If inspector find evidence that there are WMD not declared, then they can not have any confidence that the Iraq regime is being truthful and desire to have all of Iraq's WMD destroyed. %90 is not good enough and it's unlikely it's even accurate. Not only do we have to get rid of Iraq's WMD we also must ensure Iraq doesn't want to rebuild these weapons, once sanctions are lifted. Iraq's unwillingness to fully comply, indicates at miminium a lack of interest in pursuing this objective (in other words if Iraq has "given up" it's desire use WMD, it should be very eager to comply with the UN resolution, instead it's constantly resisting the UN efforts. For instance has Saddem ever apologized for invading Kuwait? Has he ever done anything to make up all the pain and misery he has inflicted? I think rather quite the opposite, he swaggers around boasting and threating and seems to find pleasure in having caused so much destruction and misery.)