below, but I thought I'd give it it own blog.
"A United States military spokesman in Baghdad refused to describe the current rules of engagement governing the use of riot control agents," according to the Times story.
But to a great extent, those rules of engagement are specified in a U.S. Army Field manual which describes the permitted uses of riot control agents in wartime and in peacetime, as well as the authority required to employ them.
The 2003 Field Manual, which is still in effect, is FM 3-11.11,
"Flame, Riot Control, and Herbicide Operations," March 10, 2003 (pdf).
The document has not been approved for public release, but a copy was obtained by Secrecy News. About 25 pages of the document, which detail the preparation of explosive devices, have been withheld from online publication by Secrecy News.