Frederick Sykes had played a central role in crafting the Royal Flying Corps (RFC's) moral, offensive and tactical approach to control of the air, yet by 1918 he embraced a vision for air power that stressed its potential as an independent force. Sykes' response indicated that in spite of an ethos that framed air power as an offensive and moral driven activity, military aviators were also aware of the multifaceted nature of the control of the air and the potential and necessity of purely localised defensive arrangements. As the RFC continued to fight a costly battle for control of the air over the Western Front, wider strategic, political and interdepartmental pressures began to mount on the Corps. Haig and Trenchard, supported by colleagues within the War Office, were able to successfully defend and prosecute the 'vigorous offensive' conducted by the RFC over the Western Front.