A US aircraft carrier group led by the USS Theodore Roosevelt entered the South China Sea over the weekend to promote"freedom of the seas" at a time of US concern about China-Taiwan tensions and Beijing asserting its maritime agenda.
The Trump and Obama administrations carried out such patrols regularly, ostensibly to challenge China's"nine-dash line" claim to jurisdiction over almost the entire South China Sea, which an international arbitral tribunal ruled has no legal basis. The United States has accused China of bullying and attempting to build a"maritime empire," announcing several rounds of sanctions on Chinese state companies involved in building artificial islands.
Vietnam and the Philippines have protested China's establishment of administrative districts in the disputed Paracel islands and in the Spratly islands. Protests also followed China's military drills near the Paracels, including the firing of ballistic missiles from several locations into waters nearby.