US President Donald Trump’s landmark visit to China comes as the Iran war disrupts global energy supplies, fuels economic uncertainty and adds fresh strain to Washington-Beijing ties. In the first part of a series examining how rivalry, interdependence and geopolitical crises are reshaping the relationship between the two powers, we look at the Arctic as an arena for competition. The Arctic is heating up, both physically and in terms of geopolitics. As Arctic warming accelerates and sea ice...