Andrew Exum puts the resignation of Afghanistan Senior Civilian representative Matthew Hoh in context. Here is the WaPo's take on the story and here (pdf) is the resignation letter. From the letter:
To put simply: I fail to see the value or the worth in continued US casualties or expenditures or resources in support of the Afghan government in what is, truly, a 35-year old civil war.
Put like that ... Ackerman has further thoughts.