By Carrington Clark, Mitch Denman Woolnough and Sookyoung Lee for ABC
The tension on the Korean peninsula has always been most palpable at the strip of land where these two nations meet - the heavily guarded Demilitarised Zone (DMZ).
While no-one knows for sure, intelligence suggests even Kim Jong-un himself may still be unvaccinated. Photo: AFP / KCNA VIA KNS
Before the pandemic, North and South Korean forces would stand face-to-face here, armed adversaries refusing to give an inch.
But coronavirus has seen soldiers from one side of the conflict take a few steps back into their territory.
"The [North Korean] soldiers still work there, but they don't come out of their buildings," said Vice Admiral Stuart Mayer, an Australian who is second in charge of the United Nation's Command which controls the area.
"If they do on the rare occasions that they must, they work in chemical protective suits and they wear gas masks."
The North Korean side of the border is unkempt, as the maintenance crews won't risk coming into close contact with the south.
What is really happening beyond the border is always a mystery.
"North Korea constantly surprises. It's called the hermit kingdom for very good reason," said Vice Admiral Mayer.
But it's clear to everyone that North Korea cannot risk an outbreak of Covid-19.
"North Korea's Covid measures are extremely strict, beyond anything that we experience in democracies," he said.
While the North has claimed to be Covid-free for the duration of the pandemic, the past 18 months has taught us that this virus will always find a way.
And recent events south of the border could have major implications for North Korea and its enigmatic ruler.
Visitors look at ribbons wishing for reunification of the Korean Peninsula on a military fence at Imjingak peace park, near the DMZ dividing the two Koreas in the border city of Paju in June, 2020. Photo: AFP
S Korea suddenly in dire straits
South Korea has recently started easing its restrictions, pivoting to a new policy of learning to live with the virus.
But since then, the situation has rapidly deteriorated.
The latest surge in South Korean cases has once again been triggered by a controversial sect.
This time, a cluster of infections spread from a little-known religious settlement led by a pastor who pokes his followers in the eyes to heal them.
South Korea is now averaging about 4000 cases a day. More worrying is the acute spike in serious cases.
Despite nearly 80 percent of South Koreans being fully vaccinated, almost two-thirds of ICU beds across the nation are full.
If the virus creeps over the border into North Korea, the country is unlikely to cope.
With a decrepit medical system, it slammed its borders shut to the world in early 2020.
While experts are sceptical of the regime's claim that they have since been virus-free, Rachel Minyoung Lee from the Stimson Centre said there are clues the situation is under control - for now.
"They continue to have large-scale gatherings, which tells me that the regime feels comfortable and confident about managing the situation," she said.
But by keeping out the virus, they have also kept out vital supplies of fuel, which is necessary for food production.
"Definitely, the food situation is difficult. Kim Jong-un mentioned that directly," she said.
Kim Jong-un has spoken in the past about food shortages in North Korea. Photo: AFP / KCNA VIA KNS
A reported exodus of the remaining foreign diplomats still in North Korea suggests the nation is continuing with its elimination strategy.
Lee said that suggests the "Covid lockdown will be in place for a while longer".
"That's why they're leaving. They don't know when the situation is going to end," she said.
North Korea has so far knocked back potential shipments of vaccine from the UN-backed COVAX facility and there are no signs it has struck a deal with its two most important partners, China and Russia.
"They maybe have trust issues with the Chinese vaccine and perhaps even the Russia vaccine," Lee said.
"I think the other issue too, is whether it can get enough doses for the entire population."
While no-one knows for sure, intelligence suggests even Kim Jong-un himself may still be unvaccinated.
Potential dangers for Kim Jong-un
Coronavirus has presented opportunities and potential threats to Kim Jong Un's power.
Experts say the North Korean ruler has long believed his country is too reliant on its neighbour China.
With their shared border closed, he has been able to push a campaign of self-reliance.
"He's a smart man and he realises that it's not a sustainable model to be overly reliant on one country," Lee said.
His recent dramatic weight loss led some analysts to wonder if he was in ill health.
But Lee suspects he is trying to consolidate his power and stave off concerns about his longevity.
"I think that was due to some strict diet regimen.
"He's now on the same footing as [his grandfather] Kim Il Sung and [father] Kim Jong Il."
But other analysts aren't so certain Kim Jong-un is doing enough to maintain his grip on power.
"There have been rumours Kim Jong-un's leadership could be re-evaluated in the next two years," said national security analyst Yun Ji-won from Sangmyung University.
She said there are even whispers of a potential coup by his little sister, Kim Yo Jong.
"It's far-fetched," Yun said.
"But the fact the rumours even exist might indicate he could potentially face a problem."
-ABC