WASHINGTON (Reuters) – The United States must remember its vow “to support the defense of Taiwan” as its democracy remains “under threat” from China, U.S. House Speaker Nancy Pelosi said in a Washington Post opinion piece published on Tuesday, moments after she arrived in Taiwan on a visit that risks bringing relations between Washington and Beijing to a new low. (Reporting by Chris Gallagher and Katharine Jackson; Editing by Caitlin Webber)