In the fall of 2006, I was riding a train through North Korea with a group of Chinese businessmen.

"Coming here is like time travel," said one of them. "It's like going back to the China of the 1970s."

A few weeks later, after I had completed my TV documentary on the country's crippled economy and left the country, North Korea conducted its first nuclear test.

In Washington, president George W. Bush described the test as a "provocative act" and called for UN sanctions.

South Korea's president Roh Moo-hyun, pursuing a decade-long effort to improve relations with the North, said mildly that South Korea was prepared to defend itself against any threat, while China, under President Hu Jintao, expressed its opposition to the test and called for dialogue.

North Korea's "Dear Leader" Kim Jong-il threatened to go to war if sanctions were imposed.

Seven years on, the players have changed, but the game remains depressingly familiar. At the same time, the intensity of all these manoeuvres has increased significantly.

Kim Jong-il has been succeeded by his son, Kim Jong-un, who looks to be closely following his father's playbook. He ordered his own personal nuclear test, North Korea's third, last month.

South Korea's new president, Park Geun-hye, who chaired her first cabinet meeting on Monday, said South Korea would retaliate if attacked.

She came to power promising to improve relations with North Korea by adopting a less antagonistic approach than her predecessor, Lee Myung-bak, who had abandoned Roh's "sunshine policy."

Meanwhile, U.S. President Barack Obama, who gave the state of the union address for his second term only hours after North Korea's latest nuclear test, pushed for new economic sanctions and these have now been unanimously approved by the UN Security Council.

China, where Xi Jinping begins a 10-year term as president later this week, unexpectedly voted for the sanctions against its protégé, then appealed for calm and dialogue.

Faced with these sanctions, Kim Jong-un, emulating his late father, is threatening war.

North Korea has threatened a pre-emptive nuclear strike to turn Washington and Seoul into "a sea of flames," renounced the armistice that ended the Korean war 60 years ago, and stopped picking up the hotline phone at the Panmunjon Demilitarized Zone, which is normally tested twice a day.

Next door, Chinese businessmen like the ones I met in 2006 — and, probably the new leadership in Beijing — are still scratching their heads and sighing over the travails of trying to do business with a Stalinist dictatorship lost in a time warp.

A real bomb

North Korea's strategy has been to advance its nuclear program, agree to tone it down in exchange for concessions and aid. Then press the repeat button.

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Beijing supported UN sanctions but China's Foreign Minister Yang Jiechi said on Saturday that sanctions were not the 'fundamental' way to resolve the tensions around North Korea, and that all sides should exercise restraint. (Kim Kyung Hoon / Reuters)

The 2006 test was something of a damp squib, whereas last month's explosion proved that North Korea has made considerable progress towards a workable, deliverable bomb.

There are suspicions, as yet unproven, that North Korea has been able to switch from plutonium to uranium, which is ominous because the country has considerable deposits of uranium ore, but only small amounts of plutonium.

As well, this time the UN sanctions are more stringent than previous ones. They include tight financial restrictions, impediments to the movement of cash and measures, including cargo inspections, to prevent North Korea from acquiring banned equipment and materials.

A list of banned luxury items, aimed squarely at the expensive tastes of Kim Jong-un and the regime's elite, includes yachts, racing cars and high-end jewelry.

North Korea's response to the sanctions, which coincide with military exercises staged jointly by South Korea and the U.S. at this time every year, has been especially shrill.

Still, past crises in this noisy and nerve-wracking stalemate have ultimately eased.

North Korea would eventually take a step back, with or without some violent gesture across the border.

Sanctions would soften. The interminable six-party meetings among the two Koreas, Japan, Russia, China and the U.S. would resume again.

And yet, each time, the world edged just a little closer to the brink of disastrous war than it was before the most recent tantrum from Pyongyang.

The vicious cycle

The reason why all the players keep on making the same moves is that none of them knows how to end the game.

North Korea's sole priority is regime survival. Kim and the generals around him are convinced that they could not withstand any substantive domestic reforms. So they will not loosen their totalitarian grip.

Believing nuclear weapons are the best protection against outsiders giving them a push, they will never give them up.

The U.S. has had one Korean War and it does not want another. While South Korea's enthusiasm for reunification is a bit like Saint Augustine's desire for chastity. They long for it, but not just yet.

The cost of absorbing the North would be an order of magnitude greater than it took West Germany to embrace East Germany. It could break the bank.

Meanwhile, China, tired of Pyongyang's nuclear shenanigans, has signed up for sanctions, but it has its fingers crossed.

Luckily for China, the UN resolution includes "credible information" clauses that will enable Beijing to use any lack of information as an excuse to avoid doing anything it does not want to do.

Sanctions that further isolate North Korea from the rest of the world actually strengthen China's hand by making it easier for it to squeeze its troublesome neighbour, adding to the leverage it already has as North Korea's only source of oil.

In a speech on Monday, Obama's national security adviser Tom Donilon suggested that North Korea should look at Burma's example, and take seriously the president's pledge to "offer his hand to anyone who would unclench their fist."

"Anyone who doubts the president's commitment needs look no further than Burma, where new leaders have begun a process of reform," he said.

However, seriously perturbed by Obama's so-called pivot towards Asia, China did not see Obama's much publicized visit to Burma as a welcome step forward, but as unwelcome evidence of a plan to "contain" China by seducing all its neighbours.

That in mind, China's new president Xi Jinping will not want to go down in history as the leader who "lost" North Korea.

Simply put, China would rather share a long border with a rogue regime than live next door to a single Korea closely allied with the U.S.

There may be new players, but do not expect the game to change anytime soon.