Wang Hongguang, former deputy commander of the Nanjing Military Region, warned that war could break out on the Korean peninsula at any time from now on until March when South Korea and the United States held annual military drills.

“It is a highly dangerous period,” Wang said. “Northeast China should mobilize defenses for war.”

Beijing, once seen as Pyongyang’s key ally with sway over its neighbor, was losing control of the situation, they warned.

“Conditions on the peninsula now make for the biggest risk of a war in decades,” said Renmin University international relations professor Shi Yinhong, who also advises the State Council, China’s cabinet.

Shi said US President Donald Trump and North Korean leader Kim Jong-un were locked in a vicious cycle of threats and it was already too late for China to avert it. At best, Beijing could stall a full-blown conflict.

China might already be preparing for the worst.

Last week, Jilin Daily, the official newspaper of the province bordering North Korea, published a full page of advice for residents on how to respond to a nuclear attack.

A document purportedly from telecom operator China Mobile about plans to set up five refugee camps in Jilin’s Changbai county also surfaced online last week.

Kim’s failure to meet Chinese envoy Song Tao during his trip to Pyongyang last month was a “humiliation” for China.