TAIPEI—The Chinese regime’s diplomatic and military pressure on Taiwan represents a threat to all democracies and the United States is committed to helping the island defend itself, Washington’s top diplomat in Taipei said. Speaking at an American Chamber of Commerce in Taiwan event late on Wednesday, Sandra Oudkirk, director of the American Institute in Taiwan which handles relations in the absence of formal diplomatic ties, said managing U.S. differences with the Chinese regime faces “distinct challenges.” “The PRC’s increasingly aggressive behaviour is nowhere more evident than in relation to Taiwan, where the PRC has continued to exert military, diplomatic, and economic pressure,” she said, referring to the People’s Republic of China, in remarks released by her office on March 31. “The PRC’s provocative military activities near Taiwan are destabilising, risk miscalculation, and undermine regional peace and stability,” Oudkirk added, at the event also attended by Taiwanese President Tsai Ing-wen. “Continued efforts by …