America's current financial strains necessitate an investigation into the effectiveness and efficiency of our fighting forces. This study explores the history of technology, theory, and doctrine development in heavy ground combat power and airpower to consider whether one force component is more efficient and effective than the other. It constructs a model from the explorative study to compare and contrast the characteristics, functions, roles, and missions associated with each force component. Next, the study explains the concepts of effectiveness, efficiency, and efficacy, and it highlights the importance of economy of force. It applies the previously developed model in case studies of Operation Desert Storm and Operation Iraqi Freedom in order to identify specific demonstrations of effectiveness and efficiency in the two force components. The model and case study reveal that it is impossible and unnecessary to compare efficacy between heavy ground power and airpower. Rather, operational planners should understand conditions that promote efficacy in each force component, and then employ each element in those conditions that play to each force component's strengths. This study ensures that each force component is employed in the most effective and efficient way possible.