I don't think the administration made up anything , wrong perhaps , but sincere.
And if there were no WMD in the past , and no potential WMD in the future you would be right to think WMD no worry since they were gone in that present, but this was just a good guess, the proof was prevented by Saddam.
If there were no WMD involved in any way at all , it would be stupid of President Bush to release Saddam at the back of an expedition to Afghanistan.
Not attacking Iraq would have been severely stupid , even if there were no Afghanistan problem to create opportunity for a Saddam backstab.
Really what behavior could have been reasonably expected of Saddam once he was released from the sanctions and airstrikes?
It is entirely a myth that Bill Clinton was not at war with Saddam Hussein , the war was ongoing , but for about eleven years it was carried forward in a very stupid manner.