The sum of all trade balances in the world is equal to zero, which means that not all countries can be net exporters – and that currency wars end up being zero-sum games. That is why America’s entry into the fray was only a matter of time.
全球贸易余额总数等于零，这意味着不可能所有国家都成为净出口国——而货币战争终归是一场零和博弈。因此，美国加入战团只是时间问题。