Recent military interventions, both peace operations authorized by the United Nations and actions by individual countries, have aimed at helping build new or reconstituted states. The legitimacy and success of these state-building interventions are often contested by local actors. Yet state-like structures are needed to ensure the rule of law and economic growth. This paper argues for a new approach: to direct the use of foreign force toward roles that helped states emerge as the most successful governance structures in historical Europe, by defending populations from outside attack, protecting them from banditry and violence, and enforcing predictable rules for commerce and civil life (while training local forces to assume these duties). This approach focuses attention on the practical need to prepare military forces for both traditional defence and police-like roles.