I’m standing at the end of the bridge to North Korea. It stops here at the border, in a riot of twisted metal. Ahead of me the piers march in pairs, on across the Yalu river until they reach the other bank. This bombed-out bridge is a tourist attraction: even now, at the end of a hard winter, a steady trickle of Chinese and South Korean tourists make the walk to the end, where you can have your photo taken with North Korea as a backdrop, or gaze at it through a telescope.

The difference between the two banks couldn’t be greater. The side I’ve just come from is the Chinese city of Dandong: neon lights, big hotels covered in white tiles and debased PoMo detailing, traffic. The other bank is the North Korean town of Sinuiju. On the skyline I’ve counted 30 smokestacks, but only ever seen smoke coming from three; by the riverbank there’s a big wheel, but in seven years of visiting, I’ve never seen it turn; there are low, grey blocks of flats, a few whitewashed buildings and a little park. Someone is welding among rusty hulks on the riverbank. It’s all very much how one expects North Korea to look.

The bridge was bombed by the Americans during the Korean War: the Chinese side is intact, but the North Koreans have left theirs in its ruined state, a monument to the destruction wreaked on their country. And to the fact that for them, the war is not over. This bridge, all concrete and girders, is a bleak enough place in winter. But what’s going on beneath my feet is positively eery. Only a few weeks ago, the river was frozen solid. Now, the thaw has begun – but only on the Chinese side. All the hot water and effluent from factories, homes and shops heats this side up. But the water on the North Korean side remains frozen, and the pack ice ends in mid-river, precisely lining the border.

For North Korea, the Cold War never thawed; the ice is a consequence of an economy on a permanent war footing, atrophied by fifty years of central planning and stunted by the stiff sanctions imposed by many foreign countries. The country’s politics seem to be cemented in a vicious circle of defensiveness. There are serious shortages of both power and food.

On the Chinese side, the entire riverfront has been made a free trade zone. This means that the most glittering part of the city is also the part that is most visible from North Korea. It’s as if two Communisms are conducting a silent architectural stand-off: the Kim Il Sung brand of Fundamentalist Stalinism (bombed-out bridge, smokestacks) versus Deng Xiaoping’s Neo-Thatcherite Revisionism (bridge as leisure attraction, skyscrapers). Both continue under their respective successors Kim Jong Il and Jiang Zemin.

A lot of Chinese tourists visit Dandong simply ‘because it’s there’. It is the only major city in China actually situated on one of the country’s external borders, and the view into another country is an attraction in itself. But there’s a further reason for coming: for most Chinese tourists, a glimpse of North Korea is the closest they can get to a visit to their own past. In the summer, tourists take boat trips almost to the other bank. They sip Cokes and gawp at the men in old-fashioned nylon suits, their red Kim Il Sung badges flashing in the sunlight, the schoolchildren in white shirts and red neckerchiefs, walking by in formation. Or they drive out of town to an entirely reconstructed stretch of ‘Great Wall’ which starts suddenly by a ticket booth on the road, and stops equally suddenly five hundred metres later, on a knoll overlooking the border: the river, fields, a small North Korean village, a pithead and two strange concrete towers with little grey spires. All suitably exotic and oppressive.

My Chinese friends in Dandong talk with mixed feelings about this interest in North Korea: a mixture of superiority and nostalgia. They’re delighted when I tell them how poor and downtrodden everyone looks in the country, and are eager to explain how miserable life was under such a system. Yet many of the same people are loyal Party members who remember the unity, the idealism and the security of the old days with great fondness. A night’s karaoke in Dandong will mingle 1950s revolutionary songs with modern pop: CDs of both sell equally well to the over-thirties.

Chinese tourists – and only Chinese tourists – can take day trips to Sinuiju itself. ‘They don’t mind showing us more than they show others,’ a friend says. ‘They know that we know what it’s like anyway, that we have been there too.’ In the main square, each tourist is asked to leave flowers at the huge bronze statue of Kim Il Sung, and is then free to photograph one side of the square, kept clean and spruce, but not the other, where the buildings are dilapidated and beggars stagger about in full view. It’s as if many of these tourists aren’t really visiting North Korea at all: they’re visiting a theme park whose subject matter is their own past. The North Koreans seem to know this, and as long as no photographs are taken, they don’t mind what is seen.

Dandong is full of a familiar, fluid layering of history. There are war cemeteries built by the Russians and the Japanese; elaborate ‘English houses’ built for the Chinese Imperial customs; old religious buildings ranging from a gingerbread Danish seminary to a classical Chinese-style mosque. The tides of history must have washed over the border, too, but North Korea portrays itself as culturally homogeneous, historically simple, fixed.

In the neighbouring province of Jilin, 250 miles upstream, there is an extinct volcano. It rises as a vast cone to 9000 feet: the pine-filled plain of its own lavafields spreads for miles around it. In its caldera is a lake, surrounded by vertical cliffs and spiney, uneroded peaks of young rock. The lake pours out of one corner, runs through the forests and becomes the Yalu River, defining the border all the way to the Yellow Sea. The Chinese call this mountain Changbaishan. It is sacred to the Koreans as one of the sites of the nation’s foundation myths: here, it is said, a legendary first Korean, Tangun, was born – the result of a union between the semi-divine King Hwanung and a bear. A kind of Korean Mount Fuji. The China/North Korea border divides the mountain clean in half, running right down the middle of the lake – a gift, it is said, to North Korea from Hu Yaobang, the Chinese Politburo member and later General Secretary. Korea is not a large country and is almost completely ethnically homogeneous; but in order to visit their sacred mountain, South Koreans must travel up through China and visit the Chinese side of the volcano – the North Korean side is closed to them.

Last summer, I went to the mountain with some Chinese friends. It was a two-day drive: a day on a newly-opened motorway followed by a day on narrow roads, followed at last by five or six hours of dirt tracks running through sub-Siberian forests. Then suddenly, a clearing: billboards for Daewoo and Hyundai, coaches, a five-star hotel. At the peak, people stand up to their knees in freezing water or gather in groups to be photographed on the banks of the lake, waving flags and singing patriotic songs. People queue to have their photographs taken against a backdrop of North Korean water and North Korean cliffs, as close as they can ever get to being in this part of their own country. In a sense, in this border region of China, you already are in Korea. The majority of the population in some areas is ethnic Korean. Little Korean Protestant churches dot the landscape. If migrants get out of the North at all, they come here, where the community is large enough to hide them – though anyone caught by the Chinese authorities is sent straight back.

Even so, North Korea has better relations with China than almost anywhere else. People in China with linguistic skills and contacts in the North provide some of the few staging posts for the country’s faltering international trade. And there are many – including, according to rumour, some very large international corporations – prepared to make modest bridgeheads into the country on the assumption that one day the last sleeping Asian tiger will awake. The economic zone in Dandong is meant to be a focus for cross-border trade; but at the moment, there’s hardly any and businesses tend to falter. Only the North Korean-run riverside restaurant is booming – and the old passenger ferry moored halfway across the river, on which the North Koreans run a gambling den (hard currency only) for the less scrupulous local Chinese. One of the biggest business deals of the last few years occurred the day after Kim Il Sung died – half of Manchuria cleaned up on the voracious demand for cut flowers from across the border.

Downstream in the Yalu estuary, the city officials have built a port. The estuary consists of marshland: bullrushes, tiny eddying clearings, and two large new concrete docks with berths for perhaps a dozen boats. In the winter, the light here can be extraordinary: at minus twenty, every drop of moisture is frozen out of the air. The sun is low, direct, piercingly sharp. Every piston, every pane of glass glistens. In the summer, it’s horribly humid. Everything drips, nothing sleeps. Local peasants fish for seafood in the channels of the marsh, balancing on huge discarded inner tubes, paddling with old ping-pong bats. They flicker between the reeds, the mosquitoes and the hulls of the visiting boats.

The port caters for smaller South Korean, Japanese and Russian vessels en route to larger Chinese ports to the south and west. A little beach has been built here, too, about ten metres long; you can hire a blue-and-white-striped beach hut, grab a meal in a metal Mongolian-style ‘beach yurt’ and survey the concrete and rust of the harbour as the fishermen paddle by. On the horizon, you can see beyond the mouth of the river to the granite hillocks and beckoning sandy beaches of the North Korean coast. The famines of the 1990s hit that part of North Korea hard: it’s odd to think that people might be starving just a few miles away. The port thrives because there are no similarly accessible ports in North Korea. Which raises one of the unspoken issues of the border: would liberalisation on the other side of the estuary necessarily be welcomed by all?

It’s easy to read the many complexities of the border area into the tourist attractions of Dandong. The ‘restored’ chunk of the Great Wall subtly emphasises the legitimacy of the Chinese claim to this side of the river. The fleshpots of the riverside free-trade zone are a brazen advertisement for the virtues of economic liberalisation. And then there’s the huge war memorial on the ridge above the city, which must be visible for miles inside North Korea, with its diorama where you can stand on an imagined hilltop and gaze over an apocalyptic wreckage of abandoned US tanks and guerrilla troop placements. In the accompanying museum there are affecting images recording the massive Chinese contribution to the war. A company of relieved-looking black American soldiers, caught in the North and on their way to the comparative safety of a Chinese-run prisoner of war camp; young Chinese volunteers improvising chopsticks from the wreckage of a downed American fighter. All these ‘attractions’ position the city as a leisure and business destination for Chinese and South Koreans, while making very visible statements to the watching eyes on the other side of the river. We are your friends. And we’re not starving.

There is another bridge over the Yalu – a railway bridge, fully functioning, and one of the only open overland routes into North Korea. It is a key staging point for the Trans-Manchurian Express, one of the oddest relics of Cold War politics. You can still get on a train in Berlin, change in Moscow, and – with the right visas and enough time – get to Pyongyang via Dandong. I coughed up the $1000 cash the Korea International Travel Company asked for a three-day visit, having waited two months for permission, and took the train across the bridge. It all happened remarkably quickly. The water turned to ice in mid-river, the empty big wheel and the riverside park slipped by, and we entered North Korea. Customs checks were interminable. ‘Excuse me, is this book important to you?’ asked a pleasant young man searching my bags, fishing out the Lonely Planet guide to Korea. ‘I am afraid this kind of book is not welcome in our country’, he added, and took it from me.

The journey onwards to Pyongyang embodied every Cold War fantasy of life behind the Iron Curtain: grey apartment blocks (many with windows empty of glass, although the temperature was well below freezing); no other trains moving on the tracks, but every station with trainloads of rusting scrap metal and UN-supplied grain; people apparently fetching water from holes in frozen rivers; hundreds digging beneath a glistening row of red flags; the coastline bristling with the outlines of tanks, muzzles lifted as if permanently ready for action; and big images of the Great Leader Kim Il Sung on buildings, inspiring slogans on concrete plinths in fields.

When we finally reached the capital, the city seemed to be in darkness. Tower blocks were just discernible, darker shapes against the moonless sky. In the main station, a few suspended light bulbs picked out shadowy crowds. Disorientation, then two figures approach: ‘Mr Jon, welcome to our country. We are your guides. We hope you will come to understand the situation here. This is not like other countries.’ I was the first Western tourist of the year. Two minders and a car were at my disposal; my hotel was a vast (and very comfortable) bronze-coloured tower block. It was inhabited by diplomats, mostly from African and South-East Asian countries; delegations from the former Eastern Bloc; a scattering of Western aid workers. From my bedroom window a city of clean, well-maintained tower blocks stretched out in all directions. People moved about with intent, stood in endless queues. A few trucks, Toyota Land Cruisers and old Mercedes moved around the streets. My minders were professional and friendly, accompanying me from eight in the morning to nine in the evening, disappearing only when I ate.

There can be no more complete monument to Stalinism than Pyongyang, almost entirely rebuilt after the war and littered with edifices ranging from the genuinely impressive to the laughably ugly. Of the nine sites we visited, seven were monuments: none were schools or factories. We took the road south from Pyongyang to Kaesong: motorway all the way, and we were the only people on it. There were frequent army checkpoints at which my hosts looked genuinely nervous, and the countryside was beautiful, if largely deserted, apart from the tanks under camouflage that seemed to line every ridge, their muzzles pointing south. Kaesong was pleasant, if poor, its historical monuments oddly lacking in any sense of age or history.

The motorway stops abruptly at the South Korean border with a checkpoint and tank traps, and an armed guard accompanies you on down a narrow tarmac track into the demilitarised zone. The DMZ is a strip of almost empty, heavily armed countryside, four kilometres wide, that cuts the Korean peninsula in two. The air was filled with propaganda, broadcast from both sides of the border. A military escort took us to a viewing hall in the enclosure within the DMZ called Panmunjom. This complex is the one ‘valve’, providing overland contact between North and South. No one crosses this border by land, but occasionally negotiations are held here.

I’ve reached the top of a flight of steps facing a small military hut. A semicircle of North Korean guards stand around the door. Each pair of eyes is focused on a different part of my body, unblinking. A few yards beyond, Americans and South Koreans and a big Post-Modern building for tourists on the other side. Inside the hut, more guards – big guns, fur hats, set faces – and a neatly set table where, every few years, the two sides have met. Peering in at each window, a GI or South Korean soldier, big dark sunglasses, hand on forehead checking the activity within. At predetermined intervals, the sides change: the North checks the outside, the South guards the inside. The power of the place is enhanced by the sense that – like the Chinese tourists in Sinuiju – I am visiting my own past. Fears I’d been delighted to forget return: emotions formed at Upper Heyford, Molesworth, Greenham Common, suddenly as urgent as if Cruise had just been delivered to the UK. History here is still frozen over.

North Korea is the only place I have ever been – outside the super-cosmopolitan cities of the West – where people don’t register a foreigner in the street. Everyone seemed intent on something, and somehow detached from each other, like figures in a Lowry painting. It was as if I was haunting, or being haunted by a country rather than actually being in it. Even style here is from the past: books and posters display the same smiling, idealistic, ‘modernised’ 1950s world familiar from both Soviet propaganda and the billboards in US suburbs. Somehow, I am sure, I am failing to really visit North Korea. The ‘old’ places seem empty, wiped of memory. The ‘new’ places, though, are charged with tension. I keep on being told of the hell of Japanese occupation, of the total flattening of the country by the Americans. Every old place has had to be renewed, they seem to be trying to say; and the new places are marked by the horror of their origin. A phrase keeps recurring. ‘The situation here is very complicated. We hope one day you will understand us.’ I become slightly paranoid, super-sensitive, watching people closely for signs of their inner life, suspicious of the way emotions jump into pre-ordained positions; fascinated by the moments of silence certain questions produce, moments where shadows of emotions I cannot discern move back and forth across faces before an answer is made.

Until the 1980s, North Korea had been ahead of China economically. The quality of its goods was highly prized across the border. The infrastructure was superior, too, with good roads and motorways. Unlike China, North Korea had successfully introduced universal literacy, free health care and education – and had never abandoned a respect for classical Korean culture. These achievements are considerable. What’s it like living here? I ask some Nigerian diplomats. Amused smiles. ‘Peaceful,’ they say. ‘Quiet and clean.’ Perhaps the reality of life in North Korea is more Surbiton without money than hell frozen over.

North Korea is unique in two respects. It has sustained a single system, more or less Stalinist, since the 1950s without any significant change in direction or political upheaval – not even Romania and Albania, the countries to which it can best be compared, managed this – and it has taken its political ideology more explicitly into the region of spirituality than any other similar country. The North Korean political philosophy, juche, has its own understanding of ideas like ‘God’ and ‘the afterlife’, which are re-interpreted as a semi-mystical integration between the political leader and people. The North Koreans claim their historical situation – the depth of their submission to Japan before the last war; the devastation by American bombing during it; and the seriousness of the threat posed by the US and its ‘puppet state’ in the South – has produced a unique set of circumstances. Simultaneously, they argue that the juche idea is a universal one – Marx updated for the late 20th century and beyond – whose time will one day come. The recent North-South rapprochement should be understood in this context. A meeting in Pyongyang between the leaders of the two Koreas is a major step by any standards. Nevertheless, Kim Jong Il, the current North Korean leader, is one of the architects of juche and is unlikely to have become a secret liberal. But he faces crippling problems with an economy dominated by military spending. The desire for improved relations with the South must be partly a result of the need to survive.

The other respect in which North Korea is unique is that it has established the only hereditary Communist dynasty by handing power from the Great Leader Kim Il Sung to his son, the Dear Leader Kim Jong Il. Behind the immense statue of Kim Il Sung in Pyongyang – ‘since our Great Leader’s death this has become our country’s most sacred site. Please act with the utmost decorum’ – is a vast relief of the mountain I climbed on the Chinese side, Changbaishan, or Paektusan, as it is called in Korean. According to the juche year 89/Year 2000 edition of the magazine Democratic People’s Republic of Korea, it is ‘the ancestral mountain … the symbol of Korea and the cradle of Korea … From the 1930s the mountain began to acquire a new meaning on top of its original symbolic meaning. In Paektu forests President Kim Il Sung mapped out the great plan to liberate Korea … and led the arduous and glorious anti-Japanese resistance.’

From some time in the mid-1980s, a new attraction at Paektusan has featured in the tourist literature and iconography of North Korea: ‘The log cabin in the secret camp on Mt Paektu’ from which Kim Il Sung is meant to have conducted his campaign. It is also said to be the birthplace of Kim Jong Il. ‘That was why Mt. Paektu became more significant place,’ the magazine continues. ‘Kim Jong Il grew up there as “son of Mt Paektu”, “son of guerrillas”, hearing the sound of guns in the flames of the anti-Japanese revolution as if a lullaby … He had extraordinary nature and outstanding predisposition from his childhood.’

The log cabin, snowbound among pines, with a peak of Paektusan behind it, is at the heart of a kind of nativity scene to be found everywhere in the country, especially on 16 February, Kim Jong Il’s birthday. Little painted models of the cabin are placed in the streets, surrounded by laudatory mottos. Perhaps it is no coincidence that Kim Jong Il’s grandparents were Christians as well as nationalists. News of the birth, it is said, ‘spread swiftly to all parts of Korea’ through the medium of inscriptions scratched by the guerrillas on the trunks of Korean pines. ‘Twenty million compatriots boast of the Paektu star’ is the translation of one such inscription; Kim Jong Il is the ‘lodestar’ that ‘rose in the sky over Mt Paektu’. The inscribed pines are preserved all around the log cabin. My magazine shows tree stumps ringed by protective tubes of perspex, capped with aluminium and a little black cotton preservative shroud.

Most external academics agree that Kim Jong Il was born in exile in Siberia. The Paektusan area was the focus of a certain amount of fighting during the Korean war, but the anti-Japanese forces – which did not organise into the present Korean Communist party until 1946 – were based over the border in Jilin Province, China. The regime is keen to establish Kim Jong Il as a product of the same generation as his father, the generation of nationalist guerrillas who, with military support from the Chinese and political guidance from the Russians, founded North Korea. What they have created in order to do this is the North Korean heritage site par excellence: new, imbued with memories of war, frozen.

The journey back to Dandong involved a 36-hour wait. Another power cut. Anticipating this, the Chinese traders on board had come armed with large quantities of pot noodle, and went up and down the train selling them to the North Korean passengers. Together we relaxed: idleness in adversity produced friendships fuelled by hard liquor. Myself, the Chinese traders, some diplomats grabbing rest and recreation in Dandong and a few hesitant North Koreans who struck up drunken conversations in quiet corners of the train. We sang ‘My Way’ together.

Soon after I get back, I take a late night walk along the Dandong riverfront to clear my head. Families and young couples are all around me, talking with relaxed animation in the freezing air. On the other side of the river a single pool of light marks the huge bronze statue of Kim Il Sung in Sinuiju town square; the rest is darkness. It should be three hours’ drive from here to Pyongyang, and another three on to Seoul, but first you have to grapple with power cuts, near-starvation and a border locked on the brink of World War Three. On the riverbank opposite, someone is welding.