Anglo-Japanese Alliance

The first Anglo-Japanese Alliance (日英同盟, Nichi-Ei Dōmei) was an alliance between Britain and Japan. It was in operation from 1902 to 1922. The original British goal was to prevent Russia from expanding in Manchuria while also preserving the territorial integrity of China and Korea. For the British, it marked the end of a period of "splendid isolation" while allowing for greater focus on protecting India and competing in the Anglo-German naval arms race. The alliance was part of a larger British strategy to reduce imperial overcommitment and recall the Royal Navy to defend Britain. The Japanese, on the other hand, gained international prestige from the alliance and used it as a foundation for their diplomacy for two decades. In 1905, the treaty was redefined in favor of Japan concerning Korea. It was renewed in 1911 for another ten years and replaced by the Four-Power Treaty in 1922.

The alliance was signed in London at Lansdowne House on 30 January 1902 by Lord Lansdowne, British Foreign Secretary, and Hayashi Tadasu, Japanese diplomat.

The Anglo-Japanese alliance was renewed and expanded in scope twice, in 1905 and 1911, playing a major role in World War I before the alliance's demise in 1921 and termination in 1923.

The main threat for both sides was from Russia. France was concerned about war with Britain and, in cooperation with Britain, abandoned its ally, Russia, to avoid blame for the Russo-Japanese War of 1904. France supported Russia economically against Japan anyway. However, Britain siding with Japan angered the United States and some British dominions, whose opinion of the Empire of Japan worsened and gradually became hostile.