I wrote about this issue here, if you want the whole argument. I don't feel like any identity is being pushed on Afghans by outsiders, but certainly a centralized government is (but contrary to popular opinion, certain Afghan rulers have had an effective level of control over the countryside). As it is, much of the tenants of centralize rule are on paper only.

I was in a lecture by an Afghan PhD who argued for devolved power. Some of the NGO set in the crowd objected at the end with the "what about the warlords?" argument. They are actually partly right, the rural elite these days is not as accountable to its constituents as it once was.

I would argue that at the moment people are still most threatened by people in and near their communities than by the central government. So if there is to be decentralization, it needs to be a gradual process. The National Solidarity Program is probably a good start.