Shachtman analyzes the Wikileaks trove. There's no evidence, however, that they were part of any ongoing program as claimed by the Bush administration:
Remnants of Saddam’s toxic arsenal, largely destroyed after the Gulf War, remained. Jihadists, insurgents and foreign (possibly Iranian) agitators turned to these stockpiles during the Iraq conflict and may have brewed up their own deadly agents...
In August 2004, for instance, American forces surreptitiously purchased what they believed to be containers of liquid sulfur mustard, a toxic “blister agent” used as a chemical weapon since World War I. The troops tested the liquid, and “reported two positive results for blister.” The chemical was then “triple-sealed and transported to a secure site” outside their base...
Even late in the war, WMDs were still being unearthed. In the summer of 2008, according to one WikiLeaked report, American troops found at least 10 rounds that tested positive for chemical agents. “These rounds were most likely left over from the [Saddam]-era regime. Based on location, these rounds may be an AQI [Al Qaeda in Iraq] cache. However, the rounds were all total disrepair and did not appear to have been moved for a long time.”
The WMD diehards will likely find some comfort in these newly-WikiLeaked documents. Skeptics will note that these relatively small WMD stockpiles were hardly the kind of grave danger that the Bush administration presented in the run-up to the war.
But the more salient issue may be how insurgents and Islamic extremists (possibly with the help of Iran) attempted to use these lethal and exotic arms. As Spencer noted earlier, a January 2006 war log claims that “neuroparalytic” chemical weapons were smuggled in from Iraq. That same month, then “chemical weapons specialists” were apprehended in Balad. These “foreigners” were there specifically “to support the chemical weapons operations.” The following month, an intelligence report refers to a “chemical weapons expert” that “provided assistance with the gas weapons.” What happened to that specialist, the WikiLeaked document doesn’t say.
I know of no incident when these weapons were actually used against US troops. And the irony, of course, is that it was the invasion that gave insurgents and Islamists access to these remnants.