The fact that such a large weapons cache missed the eye of the weapons inspectors sugests a lot more about Saddam's capabilities and intent. I understand how it is possible to Saddam to simply loose track of them, but it is very unlikely considering that his power came from his military. And it is obvious that he uses them. For a peaceful country like the US, when the last time they even used WMD's in a military action was in WWII, I would think that the loss of these things would be more likely.