That's the contention
of a think tank that people should become aware of, The Crisis Group.
, namely that the Askari shrine was probably demolished by Tandhim al- Qa’ida fi Bilad al-Rafidayn (al-Qaeda’s Organisation in Mesopotamia):
Its [the sectarian schismatic tendency's] most visible manifestation is a dirty war being
fought between a small group of insurgents bent on
fomenting sectarian strife by killing Shiites and certain
government commando units carrying out reprisals against
the Sunni Arab community in whose midst the insurgency
continues to thrive.
Now, it's a good report, well worth reading. If you can't read all 48 pages, here's
the short version. But the evidence for any connection of Zarqawi to Askari is thin. There is certainly motive.
“[Zarqawi’s group’s] central policy is to kill Shiites to trigger off a sectarian war”, Mowaffak al-Rubaie, Iraq’s national security adviser, told Crisis Group. Zarqawi,
said Wamidh Nadhmi, “started operations against Shiites from a Wahhabist ideology that is inspired by the ideas of Ibn Taymiya, which are alien to Iraqi culture.
But beyond motive, I don't see it. How does a group that has declared itself an enemy of the overwhelming majority of Shiites (called Twelver Shiites) and is regarded with fear by most Sunnis operate with such impunity in Shiite areas? How did they move around despite American troops (wasn't a curfew was in effect in Samarra?) Why didn't the shrine guards put up resistance or, if they did, what happened to them? How did the team manage to drill the shrine pillars for planting explosives in what must have been a short time without advanced equipment? Why were al Arabiya journalists covering the reaction to the bombing assassinated?
Wouldn't Zarqawi want as much coverage as possible?
It really doesn't matter to me whether the demolition of the Askari shrine was done by Zarqawi or by Jenna Bush. Despite the figleaf Iraqi government, the US is basically still an occupying power and has complete responsibility for what happens. I guess it would be very slighly more immoral if Jenna set off the primer cord. But not much. Destroying this cultural treasure was a crime against humanity.
Some of--not all, but some of-- the "conspiracy mongering" about a US role is informed speculation, which shouldn't be dismissed outright.