(Bloomberg) Presidents Joe Biden and Xi Jinping are trying to ease tensions and calm trade fights between the world's top economies. The collapse of a project in the American heartland shows just how deep a chill has set in.Biden dispatched Secretary of State Antony Blinken for a visit to Beijing and a meeting with Xi last week, and Treasury Secretary Janet Yellen is planning her own visit in July, according to people familiar with the matter. But Biden’s gestures are accompanied by a souring