Today, changing technologies, ambitious smugglers and well-funded critics of Pyongyang mean that everything from DVD melodramas to illegal Chinese mobile phones to Korean-language radio news broadcasts funded by the US government make their way into North Korea. Their presence exposes an ever-growing number of North Koreans to the outside world and threatens the underpinnings of the Kim regime.
Kim's crackdown has been largely aimed at the border with China, long the route for much of the outside information making its way into North Korea, as well as for refugees trying to get out.
Entire border security units have been replaced inside North Korea, fences have been strengthened and punishments ramped up for anyone caught trying to get through, according to smugglers, analysts and Chinese with family ties across the border. Meanwhile, special security units have been formed to seek out any contraband information or technology that Pyongyang sees as a threat.
"There has definitely been a push to roll back the tide of the flow of information," said Nat Kretchun, associate director of an international consulting group InterMedia, which released a report earlier this year about information flow into North Korea, based on surveys of hundreds of recent North Korean defectors. The study was commissioned by the US State Department.
His conclusion: North Korea is increasingly anxious to keep information at bay, but has less ability to control it.
People are more willing to watch foreign movies and television programs, talk on illegal mobile phones and tell family and friends about what they are doing, he said.
"There is substantial demand" for things like South Korean movies and television programs, said Kretchun. "And there are intensely entrepreneurial smugglers who are more than willing to fulfill that demand."
For now, though, times are tough along the border, with smugglers saying North Korean guards have become far stricter about searching for contraband.
In a country where one family has held absolute control for more than 60 years, a communist enclave that survived the downfall of the Soviet Union and a devastating 1990s famine, the notion of allowing knowledge of the larger world is deeply feared.
"Even a hint of illusion or submission to the enemy is the shortest road to death and self-destruction," Kim said in his October speech, according to the state news agency KCNA.
The enemy works out of places like Hunchun, a brutally cold, money-hungry border town of car parts shops, cavernous indoor markets piled with shiny polyester clothing and off-brand electronics so cheap it seems almost impossible. Just a few miles from both North Korea and Russia, it's a town where nearly all signs are in three languages - Chinese, Korean and Russian - and where you can find a smuggler in just a few phone calls. Even if they rarely give a name, and are often identified only by their mobile phone numbers.
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