Fought between 1904 and 1905 this war was waged between Czarist Russia and Japan for the purpose of determining which nation would be the dominant imperial power in Manchuria and Korea. The war's roots lay in the treaty concessions granted by China to Japan in 1895 at the end of the Sino-Japanese war. Russia contested the terms of the treaty and attempted to assert its control of Manchuria through military occupation of that region in the early 1900's. In addition, recently-offered treaty concessions by Korea for Russian timber extraction within northern Korea further heightened Japanese fears of Russian designs on Korea.

War broke out in 1904 with Japan breaking off diplomatic relations with Russia and launching a surprise attack on the Russian Eastern fleet stationed in Port Arthur. After the Japanese navy successfully fought this fleet and pinned the remaining elements within harbor, the Russian navy attempted to rectify the situation by sending its Baltic fleet around the Horn and into the Sea of China. This effort failed and in battle with Japanese naval forces the Russian navy was defeated. Due to these setbacks and facing a serious revolt at home, the Russian government sued for peace. Theodore Roosevelt played a key role in the negotiations between these two powers and resulted in the Treaty of Portsmouth being signed on September 5th, 1905.

Japanese success in this war resulted in the successful establishment of Japan as the dominant colonial power with East Asia and laid the foundation for their colonial empire. It can be further argued that their early success in this war, which allowed them to expand as a colonial empire, was one of the initial steps that led to the beginning for World War II with the Marco Polo Bridge incident. Certainly it is safe to say that with the successful completion of this war Japan joined the ranks of Western European nations as one of the great powers of the day.

Primary source, Comptons Online Encyclopedia