Apple is straddling a geopolitical tightrope. President Donald Trump is urging the iPhone maker to manufacture more of its electronics in the United States — and threatening it with tariffs if it does not. Chief executive Tim Cook has agreed, but has committed just a fraction of the $600 billion he has pledged to invest in the U.S. toward manufacturing. Last month he also said Apple would increase its presence in China, which has become integral to its supply chain. “China’s world