The Trump administration's tariff war with China is most often seen through the lens of the economy. But to many economists, the bigger threat is that Trump's global trade gambit will erode the United States’ main source of global authority: the long-term geopolitical relationships it has cultivated over nearly a century.

With travel warnings and revoked visas, the two superpowers locked in a bruising trade war may make students and tourists their bargaining chips.

China on Wednesday unexpectedly appointed a new trade negotiator key in any talks to resolve the escalating tariff war with the United States, replacing trade tsar Wang Shouwen with its envoy to the World Trade Organization.