As rantings from North Korea become ever more belligerent and bizarre, there are signs that China, its only outside friend in the world, is beginning to distance itself, too.
Normally reluctant to voice any sign of despair whenever tensions deepen on the Korean Peninsula, the Chinese are now talking about their "serious concern" over escalating developments there.
War-mongering rhetoric by North Korean generals and the country's young new leader, Kim Jong-un, has reached unprecedented heights. The threats have been accompanied by provocative acts such as cancelling the 60-year truce between North and South, announcing plans to restart a mothballed nuclear reactor and moving long-range missiles into better positions for attack.
Gordon Houlden, a former Canadian diplomat who has made numerous trips to Pyongyang, said he believes China is thinking seriously about getting tougher with North Korea.
"I think there has been a significant shift," said Mr. Houlden, for many years director-general for East Asia in Canada's Foreign Affairs Department and now director of the China Institute at the University of Alberta.
"It won't be easy for them [the Chinese] to change. In some ways, they're stuck between a rock and a hard place, but it's my view that they are dusting off a new approach."
He pointed to China's key decision earlier this year to back a new round of economic sanctions against North Korea, after the isolated regime launched a missile into orbit and conducted an underground nuclear test.
Perhaps more significantly, at the United Nations, China worked together with the United States – not among its closest diplomatic friends – to draw up the penalties.
"That was a clear departure from past policies," Mr. Houlden said.
And this week, as the United States responded to North Korea's moves with military manoeuvrings of its own, Deputy Foreign Minister Zhang Yesui told ambassadors from the United States and South Korea of China's "serious concerns" over the volatile situation.
Added Foreign Ministry spokesman Hong Lei: "China believes all sides must not take actions which are mutually provocative and must certainly not take actions which will worsen the situation."
That worried message could only have been aimed at North Korea, which continues to ratchet up the pressure on a daily basis.
At the same time, criticism of North Korea's extreme behaviour is becoming relatively commonplace in the Chinese media, although one editor was suspended last month for calling on the People's Republic to abandon Mr. Kim and his military cohorts.
If there is a shift in China's policy toward North Korea, it follows years of growing frustration by Chinese leaders at the headaches caused by their strange, unpredictable ally. For China, it's been all give and very little reward, and the country's new helmsmen may have had it.
More than 100,000 Chinese soldiers, including Mao's beloved oldest son, died during the bloody Korean War, when China came to North Korea's defence. In North Korea's historical recounting today, there is little, if any, mention of China's critical aid and sacrifice.
When the Soviet Union collapsed, China was left as North Korea's lone support. As a result, China provides large amounts of North Korea's trade, 90 per cent of its energy, 80 per cent of its consumer goods and nearly half of its food. Yet North Korean leaders have irritatingly resisted China's urging of economic reforms that would set the country on the road to a better standard of living.
In the face of strong Chinese opposition, North Korea continues to develop a nuclear-weapons program and pursue aggressive policies that do little more than increase military buildups by South Korea and the United States. That's hardly what China wants so close to its own borders.
While it is perceived wisdom in the West that China is key to reining in North Korean antics, actual evidence of Chinese sway is scant.
"North Koreans value their independence," Mr. Houlden said. "They don't like being dependent on anyone."
But so far, despite signalling a harder line and amid all the accompanying irritation, China is a long way from throwing its long-time fellow travellers from North Korea under the bus.
The regime's collapse would be worse for China than almost anything else. It would likely bring hundreds of thousands of refugees into China, and would put a strong U.S. ally, South Korea, in a much enhanced strategic position close to the Chinese border.
So China keeps the country afloat, suffers the indignities of being ignored when it suits North Korea and tries, somehow, to bring it to heel. "There is simply no easy solution for them," Mr. Houlden said. "They're fed up, but there is no obvious policy that would work. There's no great plan."
For China, North Korea is no fun at all. Earl Drake, a former Canadian ambassador to China who still travels there frequently, said his old acquaintances in China just shake their heads when North Korea comes up in conversation. "They sigh and tell me: 'We simply don't know how to deal with them. They're wild men.'"