China threatens to retaliate against the US after Trump launched fresh sanctions over Hong Kong, and it sets up the newest frontier in the trade war

· China said it would impose tit-for-tat sanctions against the US to punish the country for signing the Hong Kong Autonomy Act.
· The act was signed by Trump late Tuesday, and paves the way for US to punish Chinese entities responsible for imposing the new Hong Kong security law.
· Trump said that the act provides "powerful...