Tensions between the U.S. and China are at their highest in decades amid a possible unofficial meeting on Tuesday between House Speaker Nancy Pelosi and Taiwan's pro-indepedence president, Tsai Ing-Wen. The highest-ranking visit by a sitting U.S. official since Newt Gingrich in 1997 is considered by Beijing's party cadres as a hostile intervention by a foreign state in internal Chinese affairs, one which emboldens separatist forces on an island deemed by most of the world—the U.S. included—as officially part of China. Speaking to CNN's Fareed Zakaria on Monday, the chairman of Taiwan Semiconductor Manufacturing Company (TSMC) that supplies Apple its…