Russo-Japanese War

Russia and Japan fought over influence in Manchuria and Korea. Japan besieged Port Arthur, won the land battle of Mukden and destroyed the Russian Baltic Fleet at Tsushima. It was the first modern war in which an Asian power defeated a European one, and machine guns and quick-firing artillery showed what trench warfare would look like.

Outcome: Japanese victory. The Treaty of Portsmouth gave Japan Port Arthur, southern Sakhalin and a free hand in Korea.