Suppose that they did find the WMD’s in Iraq, how would they dispose of them? With chemical and biological weapons surely the act of destroying them would severely contaminate the environment.
There are currenly projects in place to dispose of American WMD’s at various places. This is as a result of various treaty obligations that we have undertaken. Chemical weapons are incinerated, as are some biologicals. Other biologicals are killed with chemicals. Nuclear weapons have the “core” removed, which is then re-processed for nuclear power plant fuel. The remainder is just high explosives, which can be handled “normally”.
There are some environmental concerns (check out the controversy over the Anniston, AL incinerator). Environmental contamination is, however, by no means as guaranteed as you imply.
A huge amount of WMD was destroyed by UNSCOM in Iraq during the 1990s.
The methods included chemical neutralization, incineration, vaporization with explosives, or dumping agents into what was apparently an open pool as part of a neutralization process.
Cite here (warning, PDF)
http://editors.sipri.se/pubs/manley_ch17.pdf