Mark
ICANN actually doesn't control the root servers, which are somewhat autonomously run by various entities around the world.
Actually it (with oversight from the US Dept of commerce) manages the contents of the root zone file. 
Those contents are then distributed by the root servers. 
As Jorge suggests, it is the need for coordinated uniqueness in top level names that creates the centralization. 
As you noted, ICANN, DoC and others exploit this need for coordination to impose political and regulatory controls on the DNS. 
It is possible, as I and others have argued, to have multiple roots, not centrally coordinated, but this also raises the risk of some incompatibilities. 

> -----Original Message-----
> From: NCSG-NCUC [mailto:[log in to unmask]] On
> Behalf Of Marc Perkel
> Sent: Saturday, November 20, 2010 11:22 AM
> To: [log in to unmask]
> Subject: [NCSG-NCUC-DISCUSS] Can ICANN be decentralized?
> 
> Just wondering.
> 
> It seems that ICANN is the point where it is most vulnerable to
> government control because it is a point where domains can be removed
> from the Internet. I'm wondering if there is a way to decentralize that,
> and if it would be a good idea to do so if it could be done.
> 
> As I understand the technology, ICANN controls the root servers. Would
> it be possible to have multiple root server systems outside of central
> control? Or is there a way ICANN can operate outside of US control? To
> be able to say NO to US law?
> 
> Just trying to think outside the box.