Russo-Japanese War, 1904–05, a war between Russia and Japan fought in Korea and Manchuria. Russia's overwhelming defeat halted its Far Eastern expansion and encouraged the anti-czarist movements that led to the Russian revolution of 1905 and the Communist revolution of 1917. Japan won new territory and emerged as a world power. The war, by showing that a nonwhite country could defeat Europeans, encouraged the rise of Asian and African nationalism that eventually led to the breakup of the European colonial empires.
Russia had long sought an ice-free, year-round port on the Pacific and desired control in China. Japan's expanding population needed territory, food, raw materials, and new markets. Both countries wanted control of Manchuria and Korea.
In 1894–95 Japan's army won from China the Liaotung Peninsula, which juts out into the Yellow Sea between Korea and China. Russia, backed by Germany and France, forced Japan to return the peninsula to China. Then, in 1898, Russia took over the peninsula—including the ice-free port of Port Arthur. Technically, Russia was only leasing the peninsula, but the presence of Russian troops and the extension of the Trans-Siberian Railway through Manchuria made it obvious that Russia intended to hold the area permanently. Russia also was extending its influence into Korea.
Japan objected to Russia's moves and, after unsuccessful negotiations, broke off relations on February 6, 1904. Two days later Japan opened the war.
The overall naval strength of Russia was greater, but the Japanese fleet was in home waters, while Russia's was divided between Europe and the Pacific. In potential military manpower Russia outnumbered Japan nine to one, but Russia was fighting 6,000 miles (9,700 km) from home and Japan was within 600 miles (970 km). Russia had only 138,000 men in Manchuria while Japan had a force of 280,000 ready for combat. The Japanese were well trained in modern warfare, and were highly disciplined and ably led. The Russians were inefficient, lacked discipline, and were hampered by unqualified officers and old-fashioned tactics.
Japan's resources were much more limited than Russia's and Japan needed to score a quick victory before the full strength of Russia could be brought to bear. Japan therefore took the great risk of starting massive troop movements immediately, before the Russian fleet at Port Arthur had been destroyed. Russia's policy was to delay and avoid decisive action until it had built up its strength.
Japan landed troops at Chemulpo (Inchon), Korea, on February 8, 1904. The Japanese fleet, under Admiral Togo Heihachiro, attacked Port Arthur February 9. Japan sank ships in the mouth of the harbor but never completely closed it. The Russian flagship Petropavlovsk was sunk by a mine, taking the life of Admiral S. O. Makarov, Russia's most capable naval officer. Naval mines cost the Japanese two battleships and a cruiser.
The Japanese army, commanded by General Kuroki Tamemoto, moved unopposed up Korea to the Yalu River and defeated the Russians in the Battle of the Yalu, April 30-May 1. Japanese troops under Field Marshal Oyama Iwao landed on the Liaotung Peninsula on May S and drove north into Manchuria, winning battles at Liaoyand and the nearby Shaho River in August and September over the Russian forces commanded by General A. N. Kuropatkin. A separate Japanese force led by General Nogi Maresuke advanced on Port Arthur.
Russia's Far Eastern fleet was defeated in August in the Battle of the Yellow Sea and the Battle of Ulsan. The fleet retreated to Port Arthur.
In the bloodiest battle of the war, November 28-December 5, the Japanese captured 203 Meter Hill, which overlooks Port Arthur. The Japanese were then able to bombard the Russian fleet, sinking it in the harbor. The Russian defenders, under General Anatoli M. Stësel, surrendered the city on January 1, 1905. On February 18, the Japanese attacked Mukden (Shenyang), the Manchurian capital, and after a furious battle took the city on March 10. The Russians retreated farther north.
Russia's Baltic fleet, under Admiral Z. P. Rozhdestvenski, arrived in the Pacific in the spring of 1905 after a seven-month voyage. It was met by Togo's fleet in the Tsushima Strait, between Japan and Korea, on May 27–28. In 45 minutes the Baltic fleet was seriously crippled, and by the next morning it was virtually destroyed.
By this time Russia was facing a revolution at home and Japan had strained its resources to the limit. When President Theodore Roosevelt of the United States offered to help make peace, both sides accepted. Representatives of Russia and Japan met at Portsmouth, New Hampshire, and on September 5 signed the peace treaty. Russia agreed to withdraw from Manchuria and ceded to Japan the southern half of Sakhalin Island and its lease of the Liaotung Peninsula. Russia also agreed to recognize Japan's dominance in Korea. For his part in making the peace, President Roosevelt was awarded the Nobel Peace Prize in 1906.