The posturing between the United States and China has been intensifying in recent weeks — China responded with condemnations and military drills after Taiwan’s president, Tsai Ing-wen, met the speaker of the U.S. House of Representatives, Kevin McCarthy. Today, Edward Wong, who covers foreign policy at The Times, explains why China is so fixated on Taiwan, and how the U.S. got in the middle of it. Guest: Edward Wong, a diplomatic correspondent for The New York Times.