Taipei (AFP) – US House Speaker Nancy Pelosi landed in Taiwan late Tuesday, defying a string of increasingly stark warnings and threats from China that have sent tensions between the world’s two superpowers soaring. Pelosi, second in line to the presidency, is the highest-profile elected US official to visit Taiwan in 25 years and Beijing has made clear that it regards her presence as a major provocation, setting the region on edge. Live broadcasts showed the 82-year-old lawmaker, who flew on a US military aircraft, being greeted at Taipei’s Songshan Airport by foreign minister Joseph Wu. “Our…