The period between 1900-1939 is said to have created the characteristics of modern war and the global order as we know it. This period saw two World Wars, political revolutions, unprecedented innovation, the introduction of a third military service and created the pre-conditions that resulted in the end of Western imperialism. As established imperial powers, both Britain and France were required to balance their imperial commitments with national political objectives and strategic imperatives, this occurred with fundamental differences. The imperial commitments of Britain and France provided both with a competitive strategic and resourcing advantage, but these existed in a dynamic global economic, social and political environment which created challenges and costs to accessing these advantages. These nations varied in their national power capacity during the period. The D.I.M.E. model (Diplomacy, Information, Military and Economic) is applied to demonstrate that the relationships among the elements of national power, specifically the balancing of constraints and opportunities offered by an empire, are interrelated and shift in utility and influence depending on circumstance and are seldom clear-cut. The capacity to yield power and achieve political objectives as a result of imperial assets is contextual. The Age of Empire ended not because of the constraints of empire or a failure to balance national interests with the responsibilities of empire but because of shifts in global ideology that meant global reach no longer equated to global power.