Manchuria Letter: Last month, when I was in the Manchurian province of Jilin, I took a detour to see one of China's most beautiful places.
Baitou Mountain, the 2,700m (8,858ft) peak of the Changbai Shan range, is an extinct volcano whose crater has been filled with an elliptical lake that feeds a massive waterfall. The lake, up to 375m deep, is the bluest blue you'll ever see and the contrast between its serenity and the violently jagged hills that surround it gives the place a sublime power.
The combination of water, sky and mountain has an almost mystical appeal in Chinese culture and the place was full of suitably reverent tourists.
A clever man had placed himself in a strategic position on the winding path just below the summit. He had two powerful telescopes, and for 10 yuan (about €1) you could have a look. He was doing a roaring trade. Everyone wanted to look through his lenses.
But the telescopes were not trained on the mountain peaks or on the eagles that sailed around them or on the lake's tranquil cobalt surface or even on the fabulous creature - the Chinese equivalent of the Lough Ness monster - that is supposed to live in its unfathomable depths.
They were focused on the strange jagged line that runs down the mountain on the far side of the lake and the blocky, almost nondescript, building that lies near its foot.
The line is a wall that marks the border between China and North Korea and the building is a military guardhouse. Through the telescope you could see the faces of the bored-looking, impassive North Korean guards.
Most of the tourists seemed even more excited by this little glimpse of Kim Jong Il's strange domain than by the awe-inspiring landscape. It was not that Koreans in themselves were exotic - much of this area of Jilin is inhabited by ethnic Koreans and there are tens of thousands of them to be met in the nearest towns and villages on the Chinese side of the border.
Instead, the curiosity of the Chinese tourists was exactly the same as my own - the slightly furtive thrill of looking into a bizarre, mysterious and forbidden territory.
And it struck me at the time that this little vignette of well-dressed Chinese tourists with the money and the leisure time to be on this side of the telescope, looking in bemusement at a place that now seems so foreign to them, was a stark image of how far China has come.
For when Chinese people look at North Korea from Chang Bai Shan, or from Dandong in the neighbouring province of Liaoning where hawkers with telescopes also do a steady trade in glimpses across the Yalu River, they are seeing not just a place but a time. Ask them what they think of North Korea and the almost-invariable reply is "It's like China in the 1970s".
The telescope takes their eyes across 2km and 30 years. An isolated country with a stagnant economy, drab buildings, few consumer goods but lots of paranoia, rigid control over everyday freedoms, a cult of personality and endless sloganising - that's North Korea today but China, in historical terms, only yesterday.
Kim Jong Il and his henchmen are the last Maoists, and this is why China's official response to North Korea's nuclear tests last week was marked by an obvious discomfort, with obvious fury tempered by a reluctance to risk a fundamental breach.
For China, North Korea is like a mad old uncle who embarrasses the hell out you but who has to be invited to your wedding because he is, after all, family. At a rational, pragmatic level, Chinese society is now much more comfortable with its old enemy, South Korea, than with its old ally, North Korea. South Korean business people are all over a Pacific Chinese city like Qingdao. South Korean restaurants are highly popular in Beijing and Shanghai.
It would suit China, and particularly the Manchurian provinces whose economies have suffered from the misfortune of bordering North Korea and eastern Russia (neither of them a dynamic economic powerhouse) if Kim Jong Il were replaced by a friendly market-oriented regime with whom good business could be done. Equally, the threat of regional instability that is posed by Kim's brinkmanship is the last thing China wants.
But the Maoists in Pyongyang can't be dumped any more than the vestiges of Maoism can be eradicated from China itself. The past is still close, and it can't be left behind until China itself has advanced further along the path of change.
The 45th anniversary of the China- North Korea friendship treaty that was signed in the wake of the Korean War was marked this summer with low-key, carefully calibrated mutual visits at vice-premier level, but it was marked nonetheless.
The regime in Pyongyang is the closest and steadiest ally that post- revolutionary China has had and it carries too many reminders of a history that has not yet been fully confronted. Only when the view through the telescope doesn't include painfully raw memories will China's relationship with North Korea be unambiguous.
