Obviously, the leaking of documents by Wikileaks is bad news if you want the U.S. to commit more troops to Afghanistan. The documents demonstrate, in great detail, how frustrating and inconclusive fighting in the country has been. However, this is, as Andrew Exum and many others have said, unsurprising and unenlightening to anyone who has been paying attention.
However, assuming that most Americans have not been paying detailed attention to Afghanistan, the documents are important in that they give the media license to show fighting in Afghanistan. The media is usually hamstrung by a lack of ability to make this case clearly — administration officials are, of course, unwilling to speak about the problems, and few people who think that Afghanistan will not improve have been to the country recently, making them difficult to pin a story on. This, by contrast, offers proof that all is not well in Denmark, and the media is seizing that opportunity to make the case (much as l’affaire McChrystal provided a similar opportunity). Even better, it offers a shadowy villain in the form of the Pakistani ISI, meaning that the story doesn’t even have to offend U.S. readers.
So this does not “demolish” COIN strategy. In fact, this shows little or nothing that was not already known (and it would be foolish to take a smattering of on-the-ground reports and establish some sort of grand criticism from it…that takes far more analysis than anyone has been able to devote to these documents yet). Rather, like Restrepo, this tells us a little bit more about the feel of the ground in Afghanistan, and puts our attention there once more.