What the best info currently available re the WMD to Syria theory says.
Addendums to the Comprehensive Report of the Special Advisor to the DCI on Iraq’s WMD (pdf) page1 (page 4 of the pdf)
ISG formed a working group to investigate the possibility of the evacuation of WMD-related material from Iraq prior to the 2003 war. This group spent several months examining documents, interviewing former Iraqi officials , examining previous intelligence reports, and conducting some site investigations. The declining security situation limited and finally halted this investigation. The results remain inconclusive, but further investigation may be undertaken when
circumstances on the ground improve.
The investigation centered on the possibility that WMD materials were moved to Syria. As is obvious from other sections of the Comprehensive Report, Syria was involved in transactions and shipments of military and other material to Iraq in contravention of the UN sanctions. This indicated a flexibility with respect to international law and a strong willingness to work with Iraq—at least when there was considerable profit for those involved. Whether Syria received military items from Iraq for safekeeping or other reasons has yet to be determined. There was evidence of a discussion of possible WMD collaboration initiated by a Syrian security officer, and ISG received information about movement of material out of Iraq, including the possibility that WMD was involved. In the judgment of the working group, these reports were sufficiently credible to merit further investigation.
ISG was unable to complete its investigation and is unable to rule out the possibility that WMD was evacuated to Syria before the war. It should be noted that no information from debriefing of Iraqis in custody supports this possibility. ISG found no senior policy, program, or intelligence officials who admitted any direct knowledge of such movement of WMD. Indeed, they uniformly denied any knowledge of residual WMD that could have been secreted to Syria.
Nevertheless, given the insular and compartmented nature of the Regime, ISG analysts believed there was enough evidence to merit further investigation.
It is worth noting that even if ISG had been able to fully examine all the leads it possessed, it is unlikely that conclusive information would have been found.
At best, barring discovery of original documentary evidence of the transfer, reports or sources may have been substantiated or negated, but firm conclusions on actual WMD movements may not be possible.
Based on the evidence available at present, ISG judged that it was unlikely that an official transfer of WMD material from Iraq to Syria took place. However, ISG was unable to rule out unofficial movement of limited WMD-related materials.
Note that "WMD-related materials"
≠ WMDs
But as WMD to Syria devotees and Bigfoot devotees are apt to say, "Absence of evidence does not equal evidence of absence. " And of course, they're both right.
However, in the meantime, folks in the reality-based community have to deal with the facts that are available and make the best decisions in light of what's known.
And, based on the evidence available at present, the WMD to Syria transfer theory seems unlikely. But, so does Bigfoot, so who's to say.