The money quote from Alexander B. Downes’ piece on the exceptionally poor track record of “regime change” interventions:
The short answer is: rarely. The reasons for consistent failure are straightforward. Regime change often produces violence because it inevitably privileges some individuals or groups and alienates others. Intervening forces seek to install their preferred leadership but usually have little knowledge of the politics of the target country or of the backlash their preference is likely to engender. Moreover, interveners often lack the will or commitment to remain indefinitely in the face of violent resistance, which encourages opponents to keep fighting. Regime change generally fails to promote democracy because installing pliable dictators is in the intervener’s interest and because many target states lack the necessary preconditions for democracy.
The failure of conservatives, in particular, to grasp the “knowledge problem” issue here is very unfortunate since it’s precisely the kind of thing they’re very sensitive to in a domestic context. But the point is that a country like Afghanistan is chock full of Afghan people who know lots and lots and lots about Afghanistan. Then you have U.S. government personnel who, from the top decision-makers in DC down to the enlisted troops on the front lines, don’t so much as speak the relevant languages. America has the preponderance of money, firepower, etc. but none of that changes the fact that local actors have all the knowledge. So rather than us (or before us the Russians) successfully using our assets to manipulate the situation, local actors wind up manipulating the assets we have to serve their own ends.