A review of official military and government websites and interviews with experts who have studied the preparations show that Beijing has implemented many of the changes in recent months after initiating them last year.
They coincide with repeated warnings by U.S. President Donald Trump that he is weighing military action to halt North Korea’s nuclear weapons program, while exerting pressure on China to do more to rein in Pyongyang.
Recent Chinese measures include establishing a new border defense brigade, 24-hour video surveillance of the mountainous frontier backed by aerial drones, and bunkers to protect against nuclear and chemical blasts, according to the websites.