On this day in 1904, Japan officially cuts diplomatic ties with Russia over disputed territories in Manchuria and Korea. Two days later, the two empires will be at war( Russo-Japanese War)
The Russo-Japanese War was fought between the Empire of Japan and the Russian Empire during 1904 and 1905 over rival imperial ambitions in Manchuria and Korea. The major theatres of military operations were the Liaodong Peninsula and Mukden in Southern Manchuria, and the seas around Korea, Japan, and the Yellow Sea.
a warm-water port
Russia sought a warm-water port on the Pacific Ocean both for its navy and for maritime trade. Vladivostok remained ice-free and operational only during the summer; Port Arthur, a naval base in Liaodong Province leased to Russia by the Qing dynasty of China from 1897, was operational year round.
Since the end of the First Sino-Japanese War in 1895, Japan feared Russian encroachment on its plans to create a sphere of influence in Korea and Manchuria. Russia had demonstrated an expansionist policy east of the Urals in Siberia and the Far East from the reign of Ivan the Terrible in the 16th century.
exchange for recognition
Seeing Russia as a rival, Japan offered to recognize Russian dominance in Manchuria in exchange for recognition of Korea being within the Japanese sphere of influence. Russia refused and demanded the establishment of a neutral buffer zone between Russia and Japan in Korea north of the 39th parallel.
The Japanese government perceived a threat to their plans for expansion into mainland Asia and chose to go to war. After negotiations broke down in 1904, the Japanese Navy opened hostilities in a surprise attack on 9 February [O.S. 27 January] 1904 by attacking the Russian Eastern Fleet at Port Arthur, China