A nation's structure and culture of civil-military relations are important and largely overlooked factors in explaining the performance of armed forces involved in complex expeditionary operations. The US model of 'Huntingtonian', divided civil-military structures and poor interagency cooperation, makes the US military less suited for complex expeditionary operations. British civil-military relations involve a Defence Ministry that conscientiously integrates military and civilian personnel, as well as extensive interagency cooperation and coordination. This 'Janowitzean', integrated form of civil-military relations makes the British military more likely to provide for the planning and implementation of comprehensive campaigns that employ and coordinate all instruments of power available to the state, as well as troops in the field displaying the flexibility and cultural and political understanding that are necessary in complex expeditionary operations.