...the Surge was a Baghdad-based troop infusion that, while allowing some more forward operations in other districts, concentrated on securing the urban centers where Iraq's sectarian violence (ie. civil war) was playing out. Kabul, on the other hand, is perhaps the only part of Afghanistan that's nominally secured. And from what I understand, most of the actual territory being contested is in the broad expanses beyond Afghanistan's few urban centers. That means that there's less of a multiplying effect as troops are spread out over broader distances.