The other argument coming out of Basra:
To the extent that the strategic goal of the Surge was to create space for political reconciliation, Basra's descent into fighting is perhaps more evidence that this goal hasn't been reached. At the same time, however, Surge advocates will be able to credibly make the argument, as I heard Fred Kagan make on NPR the other night, that what's happening in Basra in fact validates the Surge strategy by showing what happens after a precipitous withdrawal of Western forces.
The Surge didn't happen in Basra, after all, it happened in the Sunni triangle. In Basra, by contrast, British forces pulled out and left things in the hands of the Iraqis. If what is happening in Basra at the moment were happening in Baghdad, that would be much more damning stuff for advocates of the Surge. Instead, this descent into civil war is happening where our British allies pursued a strategy that is the complete opposite of the Surge.