"Yes, but they deliver BOMBS! Air to Air or Air to Ground, laser guided, bunker busting etc etc. Oh, yeah, they must have been using that MiG for weather tracking."
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I don't know if the USSR or Migs had developed LGB technology. But the point is that the existence of these 30 Migs buried in the sand doesn't prove the presence or use of WMD in themselves -- unless there is somehow evidence on these planes that they were configured to deliver chemical/bio weapons, which is unlikely since a pylon/hard point on a wing is the same for any kind of bomb.
The point in relating these Migs to WMD is that it shows Iraq was willing to bury something as large as a 60'x40'x15' Mig fighter bomber, then they could much more easily bury crates of chemical artillery rounds.
Or ship them to Syria, who will then test them in the Sudan...