Will the dollar stay dominant?

A MILE FROM the White House stands the Capital One Arena, a 20,000-seat stadium for basketball and ice-hockey games. The arena is in the Chinatown district of Washington, surrounded by Chinese restaurants and the “Friendship Archway”, built to celebrate the American and Chinese capitals becoming sister cities in 1984. One afternoon in March, this correspondent arrived at the arena and went to buy a Diet Coke from the Walgreens opposite. Once at the till she tapped on the azure blue Alipay app: up popped a QR code, scanned by the checkout worker to collect payment. The transaction took a second.