In a country where nearly every facet of society is controlled, North Korean authorities are encountering a new foe: the cellphone.
Mobile phones, which are ubiquitous in China and South Korea, are now infiltrating North Korea and are allowing information into - and out of - the "hermit kingdom."
Douglas Shin, a Korean-American minister who has been campaigning for human rights in North Korea, sees the emerging cellphone "revolution" as paralleling, if not abetting, budding dissent against the government.
"At first cellphones worked on a narrow band of land along the Chinese border," says Mr. Shin. "Now they can penetrate a great distance."
Often, he says, cellphone users must climb a hill or mountain to use them, but still he says it's possible to convey messages that previously would never have penetrated the barriers of a state that bars normal international mail and ordinary telephone calls for all but a privileged few.
Many observers say the fact that anyone can hold such long-distance conversations in North Korea could spell trouble for the country's leader, Kim Jong Il.
Shin predicts the US government may even use the spread of cellphones to help bring about regime transformation, if not change in North Korea. He predicts that the US in the next two or three years will begin sending cellphones into North Korea, just as it now plans to penetrate the North by smuggling in small radios capable of receiving Voice of America and Radio Free Asia, both official US stations.
It was shortly after the rail disaster last April in the town of Ryongchon, just 10 miles south of the Yalu River border with China, that the government imposed a ban on all cellphones. North Korean officials have suggested that the ban was intended to stop saboteurs from plotting against the North Korean regime. Kim - whose train had sped through Ryongchon shortly before two trains collided and blew up, killing several hundred people - is widely believed to have been the target.
"If possible, Kim wants mobile phones to disappear in North Korea," says Nishioka Tsutomu, a professor of modern Korean studies at Tokyo Christian University. "But North Korean people do not have enough food. To trade on the black market in China, it is essential to have a mobile phone."
Despite the ban, North Koreans have been using cellphones more than ever, according to visitors to the region. Whether crossing the border legally on official business or illegally to procure food and other vital supplies, they routinely rent or purchase phones on the Chinese side, then turn them off and hide them from border guards as they return.
Cellphones by now are in common use in Sinuiju, the North Korean city across the Yalu River from Dandong, the major Chinese center through which China does much of its trade with the North. They're also widely used along the Tumen River border in the east, and advances in technology now mean callers can occasionally reach contacts as far south as the capital, Pyongyang.
It was only last year that North Korea legalized cellphones, at least among the elite in the capital, after they had been in use illegally for several years. Now that they are illegal again, the only people who can use them legally are high-level officials and the political police.
"People make calls mostly for business," says Kim Kwang Tae, a South Korean journalist who recently visited Dandong, "but some use them for reunions of family members." Indeed, he says, those who have cellphones lend them, for a fee, to North Koreans eager to call relatives who have fled to China - or made it to South Korea at the time of the Korean War more than half a century ago.
"I've called North Koreans on cellphones from Japan," says Professor Tsutomu. "We talked about 10 minutes each time." The conversations "were secret," says Tsutomu, a critic of North Korea's regime. "I cannot say what we discussed."
Although most cellphone calls would probably not compromise security, some cellphone callers are voicing the kind of dissent that could land them in a North Korean prison. "Some people spread some negative news to outside people," says Kim. "One Chinese businessman who was living in Pyongyang said reform will not make much difference unless the leadership changes."
Dissemination of such views - not to mention actual coordination among factions plotting against the government - could pose a threat to a regime already roiled by recent high-level defections and purges, say South Korean analysts.
Kim Jong Il himself has been absent from public view for three months - prompting speculation that he's feeling insecure as he resists pressure for another round of six-party talks (with the US, China, Japan, Russia, and South Korea) on the North's nuclear program.
Kim Moon Soo, a conservative member of South Korea's National Assembly, is quick to make a connection between the cellphone revolution and a real one.
"I'm aware many defectors and refugees are using cellphones," he says. "North Korea has banned the use of cellphones, but since you can hide them easily, and many Chinese use them, it's not easy to detect them."
Clearly, "something strange is going on in North Korea," says the legislator. "A lot of North Koreans are not happy under dictatorship and are not well off, so loyalty for Kim Jong Il's regime has lessened, and they are beginning to yearn for the outside world. The leadership is having a hard time controlling people through food distributions, prison camps, and executions."
Under the circumstances, he says, "cellphones are a threat for the leadership."