At the conclusion of the Boxer Rebellion, the major powers agreed to remove their expeditionary forces from China, except for those soldiers occupying Beijing. The evacuation was completed in the fall of 1901 by all nations except Russia, which maintained a large presence in Manchuria and northern Korea. The Japanese had undergone rapid westernization at the end of the 19th century and developed a strong commercial position in China. They lacked vital domestic natural resources, iron and coal in particular, but had found those items in abundance in China. They viewed the continuing presence of Russia as a threat to their access to those valuable Chinese resources. Efforts by the great powers to ease tensions between Russia and Japan made little progress. Britain, still the dominant military force, re-deployed its Far Eastern fleet to waters closer to home in response to continuing friction with Germany. Japan quickly filled the vacuum. The Russo-Japanese War was fought on Chinese soil with China a neutral observer. Russia was anxious for the conflict, regarding Japan as militarily weak and hoping to divert attention from domestic turmoil. In February 1904, Japan struck first without a declaration of war, and attacked Port Arthur on the western extremity of the Liaotung peninsula. In the ensuing months, the world was astounded by a string of Japanese successes. The most notable encounter was the destruction of the Russian fleet in May 1905 at Tsushima Strait, the area between the Sea of Japan (East Sea) and the East China Sea. Both sides, however, desired peace. Russia was not only losing militarily, but was also experiencing a revolution at home. Japan found that its success came at the price of near bankruptcy. Theodore Roosevelt offered mediation, summoning representatives of the warring parties to Portsmouth, New Hampshire in the summer of 1905. Peace was concluded in September and provided for the following: