Do Our Goals in Afghanistan Doom Us to Fail

In the Washington Post today there is an interesting article on the "controversial" approach of training villagers as basic militias.  The idea is to let them secure their neighborhoods and provide a counterbalance to the Taliban.  What caught my eye was this quote,

"At the end of the day, how sustainable would a program like this be?" said a State Department official based in Kabul, who like other officials spoke on the condition of anonymity to discuss internal disputes. "It runs counter to the goal of giving the state a monopoly of force."

Our goal is to give the state a monopoly on force? My understanding is that Afghanistan, by and large, is tribal, with a tough terrain and almost infinitely complex communications (transportation) problems.  I understand that the Afghans who are willing to pick up a gun are a tough independent sort. Are we really thinking that centralizing power, or as they put it, giving the state a monopoly of force, will work well here?  Has AFG ever been a country with a strong central government? It just doesn't sound like a very smart goal.