The increased United States involvment in world affairs in the late XIX century and the beginning of the XX century included the following events:
Boxer Rebellion: US took part the Eight-Nation Alliance against the Boxer Rebellion (1899-1901) in China. US intervened with military troops (US Marine Corps) to save American citizens who were targeted by the rebels.
Open-Door Policy: This was a policy applied by the US government in relation to China. It was based on the principle that all foreign countries interests would be treated equally in China and no nation would try to create imperial jurisdiction over the country.
Spanish-American War: the war which was fought in 1898, started as a result of the Nationalist rebellion in Cuba against the Spanish domination and also as a result of the explosion of the USS Maine.
Japanese-Russian settlement: in 1905 after the war between Russia and Japan over their influences on China, the Treaty of Portsmouth ended the war. The treaty was achieved thanks to Theodore Roosevelt mediation.
Algeciras Conference: The Conference which took place in 1906 in Algeciras had the objective of finding a solution to the imperial crisis between France and Germany over Morocco. Theodore Roosevelt interceded to persuade the French to join the Conference.
