China's quasi-official Global Times in a column on Saturday gave three reasons why North Korea's nuclear weapons harm Beijing's interests and mentioned the prospect of regime collapse in the North, which has long been a taboo subject.

Retired major-general Luo Yuan, a prominent foreign policy hawk, wrote in the column, "It does not matter if you were a comrade and brother-in-arms in the past, if you harm our national interest then we'll get even with you."

If (a nuclear-armed) North Korea faces an attack or spirals into a regime collapse, there will be a massive influx of refugees into China, Luo wrote. "This would create a huge political and ec onomic burden on China's remote regions."

Luo added that North Korea's nuclear weapons could spur South Korea and Japan to develop nuclear weapons too, an unacceptable situation for China. He also raised concerns over radiation leaks from nuclear facilities in North Korea, whose poor economic states makes it tough to manage those facilities safely.