This chapter will examine how British military authorities viewed Japan between 1911 and 1921; how assessments of Japanese intentions and capabilities shaped British policy; and how the Anglo-Japanese Alliance affected the power of its members. It will focus on strength and strategy. That alliance is misconstrued if seen wholly, even essentially, as a diplomatic matter. Military relationships were of equal import, so too links between arms firms, in both countries bound to the state, if more so in Japan. Any decision about the Alliance might affect these components in different ways. Its renewal in 1911 served them all. For diplomats, it offered reinsurance; for soldiers and sailors, it eased deployments; for arms firms, it aided sales. The unity of outcome vanished in 1921, when Whitehall disengaged from Japan, believing it a threat against which Britain had cards, while arms firms helped the Imperial Japanese Navy (IJN) become a greater danger. This contradiction between military, naval, and military-industrial outcomes arose because the policies of British arms firms and armed forces were connected but not coordinated, whereas those of Japan were. The years 1911-1921 mark one period for arms firms, which sought to sell all they could, but three for Whitehall. Older attitudes continued in 1912-1914, marked by rising concern about Japanese intentions; during 1914-1918, Japan aided Britain but aroused anger. In 1919-1921, respect for Japanese power declined, and Anglo-Japanese relations were considered in the context of a new world order. Even more, between 1911 and 1918, Whitehall did not treat strategic relations with Japan as a coherent or central matter. Policy was loosely coordinated between specialist bureaux of the great departments, which altered their position over time. In 1916-1918, the Military Intelligence Department (MID), the intelligence services of the Government of India, and the British embassy in Tokyo, dominated analysis of Japanese threats; by 1920-1921 their positions had changed. The Admiralty said little about the matter between 1915 and 1918, but acted upon it in 1919.
Between 1911 and 1914, Britain respected Japanese power. Defence officials held Japan 'predominant' in east Asia waters. The Military Attaché, John Somerville, thought Japan likely to dominate those seas for a decade, easily able to bolster Korea and Manchuria; yet rising Russian and