Russo-Japanese War (1904-1905)

Japan and Russia clashed over influence in Manchuria and Korea. The Japanese navy destroyed the Russian Pacific Fleet at Port Arthur and then sailed around the world to destroy the Russian Baltic Fleet

at Tsushima. The Japanese army defeated Russian forces in Manchuria. President Theodore Roosevelt mediated the Treaty of Portsmouth (1905), which ended the war on terms favorable to Japan.

Significance: The first time in modern history that a non-Western nation defeated a major European power. The Russo-Japanese War electrified Asian nationalist movements, demonstrating that European supremacy was not inevitable. The defeat also weakened the Tsarist regime and contributed to the failed Russian Revolution of 1905, which would foreshadow the successful revolution of 1917.