The prevailing image of North Korea in Western minds is a closed society where the people have little sense of life beyond its borders. How, then, does one explain the mobile phones, DVDs and - most bizarrely of all - South Korean chocolate snacks.

Not a week goes by without the North Korean regime appearing to commit a fresh outrage.

This time it is an American tour guide, Kenneth Bae, sentenced to 15 years of hard labour. And for what?

Last month we were being threatened with nuclear war by a 30-year-old despot with a bad haircut.

It is no wonder the Western media tends to fall back on cliches. "Mad, bad and sad!" A "Hermit Kingdom" peopled by "brainwashed masses". I am guilty of using a few myself.

The images we see from Pyongyang tend to re-enforce those cliches. Massed ranks of soldiers goose-stepping across Kim Il-Sung Square in perfect unison.

Groups of women factory workers weeping at the sight of their young leader.

North Koreans are not nearly as isolated as we tend to think they are

"Is the adoration real or is it fear?" we ask ourselves. The images build a picture of an isolated, paranoid country, its people kept in ignorance and fear by an all-powerful militarized state.

But here are some other images that have come out of North Korea recently - a policewoman chastising the driver of a souped-up Mini-Cooper on a Pyongyang street corner. A businessman (possibly Chinese) driving through downtown Pyongyang in his Porsche Cayenne.

But the most striking image I have seen recently was of a North Korean family in a village near the Chinese border watching a South Korean TV drama on a smuggled DVD.

The trade in smuggled South Korean DVDs is huge. And it can mean only one thing - North Koreans are not nearly as isolated as we tend to think they are.

While I was in Seoul I met a number of North Korean defectors. What one of them told me left me open mouthed in amazement. It all relates to Choco Pies.

What are Choco Pies? Well, they are round chocolate snacks filled with marshmallow - a bit like a Wagon Wheel - but Korean.

And what does this have to do with North Korea?

Image caption Mobile phones - some able to make international calls - are not uncommon

A few years ago South Korea set up an industrial park just across the Demilitarized Zone in the North Korean town of Kaesong.

The factories employ North Korean workers, or they did until last month when Pyongyang shut them down.

South Korean companies were banned from paying their North Korean employees cash bonuses. So over the years they started paying them with various food products, including Choco Pies.

But instead of eating them the employees took their Choco Pies back to Pyongyang and started selling them on the black market for three to four times their original price. North Koreans, it seems, cannot get enough of the capitalist confectionery.

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So now to get back to our defector. We were speaking in Seoul shortly after the Kaesong industrial park had been shut down.

"I called my dad to tell him there was going to be a shortage of Choco Pies and the price would be going up," he said.

"I told him he should go to China and buy as many as he could find. That he should make a good profit."

All of this left me extremely confused.

"I'm sorry," I said, "you just said you called your father. Where is your father?"

"He's in North Korea," he said.

"And how did you call him?"

"On his mobile phone," he replied, as if this was the most normal thing in the world.

"Sorry, your father has a mobile phone in North Korea that can receive international calls?"

"Oh yes," he said. "It is a Chinese phone. He lives near the border so he can get on the Chinese network."

"And how common is this?" I asked.

"Very common. Everyone along the border has them. They need them for doing trade with China."

"But could he not get in to trouble?" I asked.

"Look," he said, "there are 50,000 North Koreans crossing backwards and forwards in to China to trade. There are another 100,000 living in China doing business. What's Pyongyang going to do? It could not survive without the trade."

This is a very different North Korea from the one portrayed in Pyongyang propaganda films. It is a country where the black economy is the real economy, where bribery rather than obedience is now the means of survival.

Do North Koreans still believe in the cult of the Kim dynasty? Perhaps many still do. But tens of thousands already know what life is like just across the border in China.

With smuggled DVDs and Choco Pies more are starting to glimpse what life is like in the South as well.

Pyongyang's recently-manufactured crisis does not speak of a regime that is strong and confident, but of one that is weak and scared, of the outside world, and increasingly of its own people too.

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