China’s military has begun rehearsing the encirclement of Taiwan during three days of military drills.Beijing – which views Taiwan as a breakaway province of China – called the operation a “stern warning” to the island’s government.The exercises began hours after President Tsai Ing-wen returned from a trip to the United States.The Taiwanese Defence Ministry said 42 Chinese military planes and eight ships crossed the Taiwan Strait median line.The line is an unofficial dividing line between Chinese and Taiwanese territory.