Great Britain stood as the world’s leading sea power at the beginning of the twentieth century. The British Empire stretched around the globe, the homeland, dominions, and colonies linked together by a vast network of finance, trade, communications, and naval power. Britain’s leading role on the world stage, however, was threatened by rival Great Powers growing in industrial and naval strength. Defending against these rivals confronted British leaders with a daunting strategic problem. The famed scholar, academic leader, and policy commentator Sir Halford Mackinder asserted: ‘At this moment all the great Powers are building fleets.’ He warned: ‘Nature is ruthless, and we must build a Power able to contend on equal terms with other Powers, or step into the rank of the States which exist on sufferance.’ Gerard Fiennes, a well-informed journalist covering naval affairs, echoed Mackinder’s warning: ‘the task before the [British] Empire is colossal.