Although the mix of active and reserve forces constituting the total U.S. Air Force has shifted during the last decade's force drawdown, reductions have not been proportional and may not have taken into consideration effects on other components. The authors offer a set of principles to help force planners, and programmers to recognise the implications for the cost, effectiveness, sustainability, ands popular and political support of military forces. A framework in provided or integrating the range of consideration that decision-makers face.