4 years is certainly long enough for them to have shuffled the shells long enough in their shell game that the U.N. inspectors (if allowed back, given previous restrictions placed upon them by Iraq) would have to be inhumanly lucky to stumble upon some weapons factory somewhere.

They apparently kept the inspectors away from the chemicals they used against the Kurds, did they not? If they've done it before, they can do it again, and four years of preparation isn't going to make inspections of suspicious sites any easier.

NOT.

The fact that the inspectors knew or suspected some sites proves nothing about the possible existence of other sites.

For a lot of weapon research, one wouldn't even necessarily need a constant stream of supplies. Closer to home, they still haven't found the source of the anthrax attacks, despite having the power to get search warrants almost at will. They're devoting a lot of attention to this Hatfill guy, but if in fact he is responsible, he's certainly hidden his tracks pretty well - and if it isn't him, then whoever did do it covered his or her tracks pretty thoroughly. It doesn't take too much of a stretch to think that some unobvious normal-looking building somewhere in Iraq might conceal a chemical or biological lab.