Trump administration officials are getting a second chance to try to sever ties with China by starting a trade war, imposing export controls and revoking student visas.

Secretary of State Marco Rubio said the students who will have their visas canceled include people with ties to the Chinese Communist Party and those studying in “critical fields.”

President Trump says he wants Xi Jinping, China’s leader, to call him to talk tariffs. Mr. Xi is ghosting Mr. Trump, and markets are plummeting.