Chinese leader Xi Jinping has issued a new threat to use military force in Taiwan as Beijing intensifies efforts to achieve unification with the self-governing democratic region, holding up Hong Kong as a model for Taipei...It was a notion that Taiwan’s president Tsai Ing-wen immediately rejected Wednesday amid concern that Mr. Xi is directing what Lai I-chung, who chairs the International Cooperation Council of Taiwan think tank, called a “major policy change.”