linguistic:voice_change, structural:expansion, quality:correction
Early 20th century

In 1900, the world's population had approached approximately 1.6 billion. Four years into the 20th century saw the Russo-Japanese War with the Battle of Port Arthur establishing the Empire of Japan as a world power. The Russians were in constant pursuit of a warm water port on the Pacific Ocean, for their navy as well as for maritime trade. The Manchurian Campaign of the Russian Empire was fought against the Japanese over Manchuria and Korea. The major theatres of operations were Southern Manchuria, specifically the area around the Liaodong Peninsula and Mukden, and the seas around Korea, Japan, and the Yellow Sea. The resulting campaigns, in which the fledgling Japanese military consistently attained victory over the Russian forces arrayed against them, were unexpected by world observers. These victories, as time transpired, would dramatically transform the distribution of power in East Asia, resulting in a reassessment of Japan's recent entry onto the world stage. The embarrassing string of defeats increased Russian popular dissatisfaction with the inefficient and corrupt Tsarist government.

The Russian Revolution of 1905 was a wave of mass political unrest through vast areas of the Russian Empire. Some of it was directed against the government, while some was undirected. It included terrorism, worker strikes, peasant unrests, and military mutinies. It led to the establishment of the limited constitutional monarchy, the establishment of State Duma of the Russian Empire, and the multi-party system.

In China, the Qing Dynasty was overthrown following the Xinhai Revolution. The Xinhai Revolution began with the Wuchang uprising on October 10, 1911, and ended with the abdication of Emperor Puyi on February 12, 1912. The primary parties to the conflict were the Imperial forces of the Qing dynasty (1644–1911), and the revolutionary forces of the Chinese Revolutionary Alliance (Tongmenghui).