From Somalia, Cambodia, East Timor and the Balkans in the 1990s to Iraq today, world powers have at best a mixed record when it comes to establishing functional, stable governments in countries devastated by war. The efforts have been long and costly, tangible results often hard to measure, and support for a prolonged involvement difficult to maintain.

Congressional leaders have already voiced deep skepticism about pouring billions more dollars into an American-led war that so far has shown little progress toward making Afghanistan self-sustaining.