Post-9/11 security concerns and the U.S.-led invasion of Iraq have renewed scholarly interest in nation-building as a form of externally fostered democratization. The selected works assess Iraq and its precursors, seeking general lessons for establishing new democracies. They principally conclude that successful nation-building depends on sustained commitments of time, matériel, and manpower. Although this thesis improves upon earlier studies of democracy promotion, which often treated intentions as determinative, it does not fully reckon with the effect of antecedent conditions on external intervention. As this review addresses, American efforts at nation-building have historically been enabled or constrained by local political institutions. Rather than autonomously reengineering the target society, nation-builders have buttressed bureaucracies and parliaments where they were already available (Germany, Japan) and foundered in countries that lacked such institutions (Somalia, Haiti). In sum, nation-building has been most effective when pursued least ambitiously, amid functioning states with prior experience in constitutional government.