Beijing regards the island as part of its territory, and reserves the right to annex it by force, even though the two sides have been ruled separately for more than 70 years and have deep social and economic ties. Tsai, who views Taiwan as a sovereign nation, has courted greater U.S. military and economic support since her election in 2016.
The incursions across the median line, which the U.S. established in 1954 to prevent a conflict, signal Chinese President Xi Jinping’s displeasure with Trump administration overtures to Taiwan, including the visit last week by U.S. Undersecretary of State Keith Krach. Nineteen Chinese warplanes, including fighter jets and bombers, crossed the center line Saturday, according to Taiwan’s defense ministry.