Information is more thorough on the facility history with regard in particular to chemical artillery rounds (not dissimilar to what Assad has used) here
http://en.wikipedia.org/wiki/User:Ipankonin/Duelfer_Chemical_Weapons_quotes
It does seem to be a lack of any foresight by the American military command that this facility was not dealt with, but bear in mind.
1) The facility was obviously so damaged and unstable that Saddam had decommissioned it himself. It was not apparent that the facility was a threat.
2) Nobody expected what would come later with ISIS. People were anticipating a residual force after the hard-fought gains in Iraq, a la South Korea. With a then-stable government in place, there just wasn’t a credible threat at the time.
3) I would suspect (though I have no evidence) that the facility was brought to al-Malaki’s attention. At the end of the day, a decommissioned and dangerous chemical facility is his problem, and people probably suspected him to deal with it in the interest of public safety. Obviously this didn’t happen.
With all that being said, I am sensing that this was just sloppy. Nobody wanted to do a full run-down on the complex, and with all the madness that occurred as the war wound down, people just wanted to forget about it, resign it to history as just another relic of a by-gone decade.
The most important thing to note is that if the inspection by ISG was incomplete due to the unstable nature of the facility, then the intelligence on what was inside is based off of the UNSCOM report written during the 1980s. We may not have adequate intelligence on anything manufactured between that report and Desert Storm.
As yourself I too sense a sloppiness. Unacceptable IMO, but here we are facing a repeat performance due that sloppiness I believe we can attribute to the deliberate choreographed hinderance employed by the Leftist Democrats at the time, and the currently Leftist Democrat/Obama factor.
Thanks for your response.