'The left blogosphere seems to have wigged out over the suggestion that George W. Bush and the successful emergence of a secular, democratic Iraq has anything to do with all this [Tunisia]. For starters, it is amusing to see that those voices, fresh from the smear on conservatives regarding the Arizona shooting, are now all about "causation." But more seriously, had democracy failed in Iraq, had the country descended into chaos, and had Iraqis laboring for a secular, democratic Muslim country been killed and exiled, do we imagine this would have been good for the prospects of democracy elsewhere? Recall that it was the left that said that democracy was alien to the Middle East. Bush was right; they were wrong. - Jennifer Rubin'
As Larison observed, Iraq did descend into chaos and many secular and middle class Iraqis were driven out of the country, in droves. But the other point here is that the argument, as I understand it, was never about some innate Arab capacity for self-rule but about the institutional structures that would enable it to grow successfully, and whether it was possible to justify the U.S. invasion and occupation of the country on the grounds that doing so would help implant those institutions - and to America's lasting benefit.
Stating the obvious - that the Arab world didn't have a lot of the institutions necessary to make democracy work - isn't the same thing as saying that Arab states are incapable of creating them over time, that they are "undeserving" of them or that they are somehow incapable of functioning in a democratic society.