The South tries to get information into the North, and North Korea's leader Kim Jong Un tries furiously to block it, as he attempts to shield his people from outside information.

North Korea is the only country in the world the internet has not penetrated. All TV channels, radio stations and newspapers are run by the state.

"The reason for this control is that so much of the mythology around the Kim family is made up. A lot of what they tell people is lies," says Martyn Williams, a senior fellow at the Washington-based Stimson Center, and an expert in North Korean technology and information.

Expose those lies to enough people and the regime could come crumbling down, is how the thinking in South Korea goes.

The loudspeakers are one tool used by the South Korean government, but behind the scenes a more sophisticated underground movement has flourished.

A small number of broadcasters and non-profit organisations transmit information into the country in the dead of night on short and medium radio waves, so North Koreans can tune in to listen in secret.

Thousands of USB sticks and micro-SD cards are also smuggled over the border every month loaded with foreign information - among them, South Korean films, TV dramas, and pop songs, as well as news, all designed to challenge North Korean propaganda.

But now those working in the field fear that North Korea is gaining the upper hand.

Not only is Kim cracking down hard on those caught with foreign content, but the future of this work could be in jeopardy. Much of it is funded by the US government, and has been hit by US President Donald Trump's recent aid cuts.

So where does this leave both sides in their longstanding information war?

Every month, a team at Unification Media Group (UMG), a South Korean non-profit organisation, sift through the latest news and entertainment offerings to put together playlists that they hope will resonate with those in the North.

They then load them onto devices, which are categorised according to how risky they are to view. On low-risk USBs are South Korean TV dramas and pop songs - recently they included a Netflix romance series When Life Give You Tangerines, and a hit from popular South Korean singer and rapper Jennie.

High-risk options include what the team calls "education programmes" – information to teach North Koreans about democracy and human rights, the content Kim is thought to fear the most.

The drives are then sent to the Chinese border, where UMG's trusted partners carry them across the river into North Korea at huge risk.

South Korean TV dramas may seem innocuous, but they reveal much about ordinary life there - people living in high-rise apartments, driving fast cars and eating at upmarket restaurants. It highlights both their freedom and how North Korea is many years behind.

This challenges one of Kim's biggest fabrications: that those in the South are poor and miserably oppressed.

"Some [people] tell us they cried while watching these dramas, and that they made them think about their own dreams for the very first time", says Lee Kwang-baek, director of UMG.

It is difficult to know exactly how many people access the USBs, but testimonies from recent defectors seem to suggest the information is spreading and having an impact.

"Most recent North Korean defectors and refugees say it was foreign content that motivated them to risk their lives to escape", says Sokeel Park, whose organisation Liberty in North Korea works to distribute this content.

There is no political opposition or known dissidents in North Korea, and gathering to protest is too dangerous – but Mr Park hopes some will be inspired to carry out individual acts of resistance.

Kang Gyuri, who is 24, grew up in North Korea, where she ran a fishing business. Then in late 2023, she fled to South Korea by boat.

Watching foreign TV shows partly inspired her to go, she says. "I felt so suffocated, and I suddenly had an urge to leave."

When we met in a park on a sunny afternoon in Seoul last month, she reminisced about listening to radio broadcasts with her mum as a child. She got hold of her first K-drama when she was 10. Years later she learnt that USB sticks and SD cards were being smuggled into the country inside boxes of fruit.

The more she watched, the more she realised the government was lying to her. "I used to think it was normal that the state restricted us so much. I thought other countries lived with this control," she explains. "But then I realised it was only in North Korea."

Almost everyone she knew there watched South Korean TV shows and films. She and her friends would swap their USBs.

"We talked about the popular dramas and actors, and the K-pop idols we thought were good looking, like certain members of BTS.

"We'd also talk about how South Korea's economy was so developed; we just couldn't criticise the North Korean regime outright."

The shows also influenced how she and her friends talked and dressed, she adds. "North Korea's youth has changed rapidly."

Kim Jong Un, all too aware of this risk to his regime, is fighting back.

During the pandemic, he built new electric fences along the border with China, making it more difficult for information to be smuggled in. And new laws introduced from 2020 have increased the punishments for people who are caught consuming and sharing foreign media. One stated that those who distribute the content could be imprisoned or executed.

This has had a chilling effect. "This media used to be available to buy in markets, people would openly sell it, but now you can only get it from people you trust," says Mr Lee.

After the crackdown began Ms Kang and her friends became more cautious too. "We don't talk to each other about this anymore, unless we're really close, and even then we're much more secretive," she admits.

She says she is aware of more young people being executed for being caught with South Korean content.

Recently Kim has also cracked down on behaviour that could be associated with watching K-dramas. In 2023 he made it a crime for people to use South Korean phrases or speak in a South Korean accent.

Members of 'youth crackdown squads', patrol the streets, tasked with monitoring young people's behaviour. Ms Kang recalls being stopped more often, before she escaped, and reprimanded for dressing and styling her hair like a South Korean.

The squads would confiscate her phone and read her text messages, she adds, to make sure she had not used any South Korean terms.

In late 2024, a North Korean mobile phone was smuggled out of the country by Daily NK, (Seoul-based media organisation UMG's news service).

The phone had been programmed so that when a South Korean variant of a word is entered, it automatically vanishes, replaced with the North Korean equivalent - an Orwellian move.

"Smartphones are now part and parcel of the way North Korea tries to indoctrinate people", says Mr Williams.

Following all these crackdown measures, he believes North Korea is now "starting to gain the upper hand" in this information war.

Following Donald Trump's return to the White House earlier this year, funds were severed to a number of of aid organisations, including some working to inform North Koreans. He also suspended funds to two federally financed news services, Radio Free Asia and Voice of America (VOA), which had been broadcasting nightly into North Korea.

Trump accused VOA of being "radical" and anti-Trump", while the White House said the move would "ensure taxpayers are no longer on the hook for radical propaganda".

But Steve Herman, a former VOA bureau chief based in Seoul, argues: "This was one of the very few windows into the world the North Korean people had, and it has gone silent with no explanation."

UMG is still waiting to find out whether their funding will be permanently cut.

Mr Park from Liberty in North Korea argues Trump has "incidentally" given Kim a helping hand, and calls the move "short-sighted".

He argues that North Korea, with its expanding collection of nuclear weapons, poses a major security threat - and that given sanctions, diplomacy and military pressure have failed to convince Kim to denuclearise, information is the best remaining weapon.

"We're not just trying to contain the threat of North Korea, we're trying to solve it," he argues. "To do that you need to change the nature of the country.

"If I was an American general I'd be saying 'how much does this stuff cost, and actually that's a pretty good use of our resources'".

The question that remains is, who should fund this work. Some question why it has fallen almost entirely to the US.

One solution could be for South Korea to foot the bill - but the issue of North Korea is heavily politicised here.

The liberal opposition party tends to try to improve relations with Pyongyang, meaning funding information warfare is a no go. The party's frontrunner in next week's presidential election has already indicated he would turn off the loudspeakers if elected.

Yet Mr Park remains hopeful. "The good thing is that the North Korean government can't go into people's heads and take out the information that's been building for years," he points out.

And as technologies develop, he is confident that spreading information will get easier. "In the long run I really believe this is going to be the thing that changes North Korea".

Top image credit: Getty