From our own Steve Schippert last week in Dangerous Liaisons:
...gracing the pages of the New York Times’ International Herald Tribune is a commentary, Hezbollah and Al Qaeda, by a researcher and a senior fellow at the Brookings Institution’s Saban Center for Middle East Policy which attempts to dispel the notion of al-Qaeda – Hizballah (and thus, Iranian) cooperation....
AL-QAEDA leaders in Iraq are planning the first “large-scale” terrorist attacks on Britain and other western targets with the help of supporters in Iran, according to a leaked intelligence report. (emphasis mine)
There is no shortage of articles and reports that attempt to dismiss connections between Sunni and Shia groups. Thankfully, those of us who assume the role of Devil's Advocate have ample evidence from which to draw. Unfortunately, while the contrarians risk a charge of animal cruelty for beating a dead horse, peddlers of the demonstrably false are still viewed as unassailable experts.
In the intelligence business people love to talk about the importance of history. No one wants to doom themselves and their supported policymakers by repeating bad history; everyone cherry picks their favorite historical example to support their conclusions about present-day affairs. The danger of course is that if you are basing your conclusions on bad historical information, you're not avoiding doom, you're driving straight for it.
Proponents of the "Sunnis don't work with Shias" meme will no doubt point out that the inter-faith cooperation we see today is a historical anomaly, but history is not just a catalog of the past, it is a map of myriad evolutions. Good analysis doesn't repackage the past, it attempts to predict the future, which makes looking too far back a mistake and a disservice.
Of course drawing conclusions based on incomplete information is a risk all external commentators run, regardless of how well documented their findings. However, if recent history has taught us anything, it is the importance of the seemingly implausible that lies right in front of our faces.