In the 1870s Great Britain was the 'top' nation, possessing a flourishing industrial economy, the strongest naval force, the finest merchant fleet and the biggest empire the world has ever known. Even by 1914, among the Great Powers, Britain alone possessed territories and interests in every part of the globe. There were many emulators in maritime and colonial fields, but no rivals for pre-eminence. Those responsible for conducting the foreign policy of such a state were bound to work for ensuring the security of the homeland as well as for maintaining its Great Power status. This conditioned their perceptions and hence the conduct of relations with other European powers.
As in all states in all ages, British statesmen formulated their foreign policy with the aim of ensuring the sovereignty and territorial integrity of the British Isles. In the post-1870 scenario when each 'Great Power' of Europe faced the possibility of direct attack from at least two powers, British statesmen had far less anxiety on this score. So long as they could ensure the predominance of their navy, their country's geographical position as an island off the north-west coast of Europe made their country immune to any threat of invasion. Their main concern was that the lowland region near the North Sea, forming the lower basin of the Rhine, Meuse and Scheldt rivers, corresponding to modern Belgium, Netherlands and Luxemburg, should remain free from domination by another major power. It was both an economic and a strategic question because it involved the effective flow of goods in and out of Britain as well as fear of invasion proper. Under a treaty signed in 1839, five powers - Britain, France, Russia, Austria and Prussia - had guaranteed the neutrality of Belgium. This implied that if any of the guarantor states infringed that neutrality, each of the others could claim a right (and in certain circumstances would have a duty) to resist the infringement. 1 In 1870, at the time of the Franco-Prussian War, Belgium's neutrality was re-affirmed when both France and Prussia respected it and Britain reiterated that it accepted its responsibilities as a guarantor.