With all their strength and energy, the North Korean defectors hurl the bottles into the ocean.

Filled with rice and packaged alongside waterproofed bibles and USB flash drives, the bottles land one after the other splashing into the water and forming a trail of plastic as the current carries them towards their senders’ isolated homeland.

It is not long before the mound of bottles on the shore, piled high in anticipation of the turning of the tide, has disappeared. Set adrift from this small island straddling the border with the North, the subversive packages do not have far to travel.

With luck, North Koreans on the other side will soon have rice to feed their body, scripture to feed their soul, and information about the outside world to feed their mind.

“We lived in North Korea so we understand their mentality and mindset,” says Park Jeong-ho, one of the organisers of the event, which is aimed at penetrating the North’s information blockade.

“We know exactly what kind of content will break down their propaganda and brainwashing so that kind of information has been included on the USBs. The bottle of rice is not that big, so it might feed them for a day. But if they get information from a USB, it can change their lives.”

The bottle launch, part of the annual North Korea Freedom Week organised by the North Korea Freedom Coalition, comes just days after the historic meeting between South Korean President Moon Jae-in and North Korean leader Kim Jong-un.

At the summit, the first between the leaders of the two Koreas in more than a decade, Moon and Kim signed an agreement pledging to work together to formally end the Korean war and denuclearise the peninsula. Despite previous periods of rapprochement ending in belligerence and sporadic violence by the North, a rare degree of optimism has taken hold in the South this time around.

It’s no joke: the North Korean nuclear crisis could get Trump the Nobel Prize

Moon’s liberal government has declared the present moment a “new start for peace”. Many South Koreans reported being impressed by Kim’s humble demeanour during the summit, which was packed with symbolism emphasising the divided countries’ common heritage – even the soil used to plant a pine tree at the truce village Panmunjom was taken from the two most famous mountains on either side of the border.

In the last week, the Unification Flag, which depicts a blue Korean peninsula against a white background, has sprung up in public spaces across the country ranging from district offices to city buses. An opinion poll carried out by Realmeter after the summit found that nearly 65 per cent of South Koreans trusted North Korea to relinquish its nuclear weapons and pursue peace, compared to just 15 per cent before. More remarkable still, 78 per cent of South Koreans told another pollster that they trusted the North Korean leader, up from 10 per cent six weeks earlier.

The one thing that won’t be discussed at the Korea summit

Park and his fellow activists share no such optimism about the current thaw in inter-Korean relations and remain unwaveringly cynical about the regime’s intentions.

“We believe the summit was a pure political show to legitimise the North Korean regime in the eyes of the international community,” says Park, who fled Hyesan, a small city on the Chinese border, in 1998. “Whether it is President Trump or President Moon, they have their term. After four or five years, they will be replaced by other people. But Kim Jong-un will remain in that seat forever unless the regime ends.”

Defectors like Park are determined to see an end to the Kim family’s seven-decade-long stranglehold on power. They’re adamant that the best way to make that happen is to show North Koreans the reality of the outside world and expose the regime’s propaganda as lies. This year’s North Korea Freedom Week was aptly themed, “The truth will set them free.” Among other content, the latest batch of USBs sticks sent to the North contained South Korean soap operas, biblical animations and Donald Trump’s speech last year to South Korea’s National Assembly.

“We want peace and freedom for the North Korean people,” Park says, scoffing at renewed discussion in South Korea of a permanent peace between Pyongyang and Seoul. “This is our attempt to reach them and give them hope.”

Despite the South’s outreach to the North having strong public support here, many defector activists see it as nothing short of a betrayal. While addressing denuclearisation and family reunions, the summit, the third following meetings in 2000 and 2007, did not refer to the human rights situation inside the reclusive dictatorship. A 2014 UN Commission of Inquiry detailed a raft of abuses inside North Korea, including murder, torture, enslavement, rape and forced abortions, that it said were without “parallel in the contemporary world”.

“The summit was just for the regime, not for the people,” says Jung Gwang-Il, another organiser and a North Korean prison camp survivor. “I was disappointed nothing was discussed to do with North Korean human rights. Human rights are not a huge political issue, it’s for the everyday lives of the North Korean people. It has been totally washed out of the summit agenda, which is a huge worry.”

Jung, who survived torture at Yodok political prison camp, sees no improvement in human rights in his homeland under Kim, the Swiss-educated, third-generation leader who came to power in 2011.

Hang on, what language is Kim Jong-un speaking?

“It’s getting worse,” says Jung, who runs defector-led activist group No Chain for North Korea. While the meeting between Moon and Kim moved many South Koreans to tears, Jung refused to watch it. “I’m really angry,” said Jung of the warming attitudes among South Koreans toward the North. “Everyone is talking about peace, but it’s not true peace. It’s a delusion.”

Jung, who is travelling to Washington later this month to deliver a list of names of known prison camp inmates to President Trump, isn’t only concerned about the South ignoring the plight of ordinary North Koreans. Many activists in fact fear the Moon administration will try to shut down their activism if it seems to be getting in the way of inter-Korean reconciliation. Under past left-leaning governments, including that of Moon’s political mentor Roh Moo-hyun, defectors regularly complained of being silenced as part of the “Sunshine Policy” that prioritised dialogue and cooperation with Pyongyang. Hwang Jang-yop, the most high-ranking North Korean official to ever defect, was barred from travelling to the United States during the 2000s to prevent him from criticising the regime overseas.

“The issue of the South Korean government trying to intimidate, silence or pressure defector voices is not a new thing but something that goes back to the Sunshine days,” says Hyun S. Song, the North American director of No Chain.

A number of recent developments hint that fears of a crackdown on anti-regime activism may be justified. Last month, Thae Yong-ho, the most high-profile defector in the South, was blocked by South Korean intelligence agents from answering journalists’ questions after speaking at a private conference on North Korean human rights. Video footage of the incident, which appeared to show Thae willing to engage with the media, subsequently disappeared from a local news channel’s website without explanation. Thae, who was Pyongyang’s ambassador to Britain before defecting in 2016, had previously given interviews in which he espoused hardline views on the North that contrasted with Moon’s pro-engagement agenda.

“Thae Young-ho is already being muzzled, and other activist defectors are fearing that they too will be pressured to keep quiet,” says Song.

In a possible indication of things to come, the summit declaration included a pledge to cease “all hostile acts” between the Koreas. “Hostile acts,” the agreement made clear, would include loudspeaker propaganda broadcasts and sending leaflets across the border. On Monday, the Ministry of Unification, which manages relations with Pyongyang, announced it had requested activists to stop sending balloons containing anti-regime leaflets to the North. In the eyes of many, the announcement sounded less like a request than a threat. Under previous administrations, the government has on occasion resorted to arresting activists on national security grounds. “Of course I am worried that our work to overthrow the regime will be undermined,” says Jung. “I was worried police would show up to stop today’s launch but fortunately they didn’t. We’ll see what happens in the future.”

However Seoul responds, it’s clear that activists like Jung won’t be dissuaded from their mission. For the North Korean escapees gathered on this rocky outcrop in the Yellow Sea, it is their brethren back home, not the government in their adopted home, that is their concern.

“I always miss my hometown,” says Jung, his eyes pointed toward the grey sky. “I want to go back, but the reality is I can’t.”