Robert Kelly is an American living in South Korea. As is well known to the more than 25 million viewers who've watched the hilarious video of his children bursting into his BBC interview, the Korea expert has a young family.
While Kelly is sceptical that tensions over North Korea's nuclear program will lead to war, he and his wife regularly discuss what they will do if there is an attack by the North on Busan, where Kelly teaches at the city's university.
"With a young family I take it seriously and my wife and I talk about it whenever these things pop up – what to do, where to go, what to pack," he said.
Busan in the south would be in range of the North's ballistic missiles, including nukes. The THAAD shield system might stop some of them but not all.
There is no such protective shield to defend the capital Seoul against the rain of artillery and rockets that could be fired by the North from the demilitarised zone. In greater Seoul, which the North has threatened to turn into "a sea of fire" if it were ever attacked, there are an estimated 100,000 Americans living among the population of 25 million people.
The Trump factor
If Donald Trump lost patience with the North's recalcitrance over its nuclear program and decided to launch a pre-emptive strike against the regime of Kim Jong-un, he would have to consider whether he wanted to see images of hundreds, maybe thousands of dead Americans on CNN on top of the tens of thousands of dead South Koreans.
He could evacuate Americans en masse but that would signal an intention and the North would then probably launch pre-emptively anyway.
This is just part of the devilish difficulty that military planners face as they try to keep "all options on the table" as the Trump administration insists it is doing. Nobody is surprised by this language – diplomatic pressure is hardly persuasive without the ultimate threat of force to back it up. The problem as Bruce Bennett, a Korea expert from the RAND Corporation, points out is that "there are no good military options".
It would be a war unlike any seen in generations, indeed perhaps ever if it were to go nuclear, which is entirely possible since many of the top experts believe the North already has the ability to fit a miniaturised fission device onto a medium-range missile.
On paper, North Korea's military is the fourth-largest in the world, and US Defence Secretary James Mattis has said that "if this goes to a military solution, it's going to be tragic on an unbelievable scale".
If it came to that, Australia would likely be involved. Under the 1953 armistice, Australia would as a signatory be expected to support South Korea if it was invaded by the North, some experts say. Indeed the United Nations force based in Japan to support South Korea is currently commanded by an RAAF officer.
A spokesman for Defence Minister Marise Payne would not comment on "hypotheticals about what Australia might do in the event of a contingency on the Korean Peninsula". But he said the Armistice agreement was "not a mutual defence agreement".
Australian Strategic Policy Institute head Peter Jennings said that because of the US alliance and Australia's close economic relationship with South Korea, "we've got a big stake in the fight whether we like it or not".
For now, the ball is in the court of the US and its allies in the sense that the North is cheerfully moving ahead with its nuclear and missile testing, shifting the balance day by day and making the calculus more difficult for the international community.
So what are the near-term options for the US, South Korea and their allies, such as Japan?
One that is most often suggested is some kind of surgical strike to take out the North's nuclear and missile facilities as well as its other most-threatening military assets. The problem with this is that it could not be done quickly or cleanly. Many of the nuclear sites and artillery and rocket batteries are dug into mountainsides and either hardened against attack or hidden.
It would take days, probably weeks, and involve hundreds of strike aircraft and missiles such as Tomahawks fired from US ships in the Sea of Japan. Meanwhile the North would hit back with everything it had.
"People think we can fly in there or shoot some cruise missiles from the Sea of Japan and cleanly take them out," Kelly said. "It's not going to be like that. You're going to have to bomb the hell out of North Korea. That's not a surgical strike, that's a war.
The notorious "Mother of All Bombs" that was dropped on the Taliban recently, Kelly says, was actually a signal to North Korea – a view shared by many experts. That's the kind of firepower you'd be talking about, he says.
Euan Graham, who once served as Britain's charge d'affaires in Pyongyang and now heads the Lowy Institute's international security program, has travelled through the area and makes the same observation about the North's batteries of artillery along the demilitarised zone that are aimed at Seoul just 40 kilometres away.
"You see a little tunnel open at the base of a hill. That would be extremely difficult to close down. You'd need precision strikes otherwise they could just keep going in and out and resupplying theoretically until they ran out of ammunition."
The ability to rain artillery down on the South's capital is really Kim Jong-un's trump card. A 2012 Nautilus Institute report found that the North could fire 4000 rounds of artillery an hour, which could kill 64,000 people on the first day, mostly in the first three hours.
They would also likely target US military bases in South Korea and Japan.
The US and its allies could also consider a limited punitive strike against the Kim regime, a way of telling it to stop its nuclear program or it can expect more of the same – something like what Trump did to the Syrian regime after its use of chemical weapons.
But can a hermit dictatorship see the difference between a limited and an all-out strike? The Kim dynasty has always been regarded as rational and occupied first and foremost with its own survival, though the current dictator is more reckless and provocative than his father or grandfather.
But the regime is paranoid, experts agree.
"An autocratic dictatorship like that is not socialised to trust or believe any kind of reassurances," said Daniel Pinkston, formerly with the International Crisis Group in Seoul and now at Troy University. "They're not going to believe we're committed to a limited operation … They're as likely to see it as the first stage of regime change and respond accordingly. We'd need to be prepared to use more force in return so I don't see how you can credibly commit to a limited strike."
The complex mechanism of deterrence and pre-emption between the North and South is a hair-trigger affair.
Pulling the trigger first
Late last year after seeing a string of nuclear tests by the North, Seoul unveiled a three-pillar policy to counter the threat. It consists of a "kill chain" system to carry out a pre-emptive strike against the nuclear facilities if the South is faced with an imminent threat, an air defence system to shoot down missiles and finally the "Korea massive punishment and retaliation plan" – whose name rather speaks for itself.
Bennett says this pulls both sides towards a tendency for "pre-emption of pre-emption" – jumping before the other side does.
The North meanwhile has an inbuilt incentive to escalate because its strengths are its heavy artillery and missiles, ultimately its nukes, whereas its conventional land forces are a case of quantity rather than quality and its air force is antiquated.
The South meanwhile has the US 8th Army's 2nd Infantry Division made up of American and Korean troops – including US special operations forces – backed up quickly by Marines from Okinawa.
The Lowy's Graham says that some kind of repeat of the 1950s Korean War is unlikely. A report last year from the Centre for Strategic and International Studies similarly said that the peninsula's mountainous terrain combined with marshland and rice fields would force heavily armoured forces to use a handful of predictable routes.
That said, the North does have a large number of special forces troops and is thought to have dug tunnels under the DMZ through which troops could pour.
"The North would want to insert special forces deep into the South to wreak havoc and create problems, taking down the power grid or critical infrastructure … so that they might be able to create fear and undermine confidence in society," Pinkston said.
But overall, experts agree, the North's land forces would struggle. And in fact it is the weakness in the conventional domain that creates the risk the regime would go from nought to 100 rapidly and use its comparative strengths in rockets and missiles, including nukes.
"What makes North Korea dangerous is its very weakness," said Graham. "It has no strategic depth, its conventional forces are no match for the [South Koreans] let alone the US and so there is the force of logic of escalation."
This makes any idea of containment extremely difficult even if conflict starts from a simple miscalculation or accident.
As Bennett put it: "You have a very low degree of crisis stability."
And Pinkston added that "time is compressed because of the geographic proximity". In other words, with Seoul just 40 kilometres from the DMZ and Pyongyang about 135 kilometres from the zone, nobody has much time to think about how to respond in a crisis.
There is a common thinking among experts who spoke to Fairfax Media that Pyongyang might subscribe to the old Cold War thinking of "use it or lose it" regarding its nuclear weapons. Kim would know they are his enemies' prime target.
"We have to assume that fairly early they are going to use them," Bennett said.
The North also has large stockpiles of chemical and probably biological weapons.
China's red line
Where it gets "really interesting", Bennett continued, is in China's response. It is disconcertingly unclear because despite US efforts to sound Beijing out, the Chinese leadership has been reluctant to reveal where its own red lines are.
China needs North Korea as a buffer so that it doesn't have US or pro-American forces from South Korea on its own border. Therefore, Graham explains, a land occupation by the US north of the 38th parallel is generally seen as China's red line but then how far north is unclear.
Pinkston says, "I can't see China sitting back and doing nothing".
While the US and China would work hard to avoid some miscalculation between them, the thought of Chinese and US troops facing off even with a buffer between them would prickle nerves in the region.
The other real problem is that the options are getting worse rather than better for the US and its allies as the North nears its goal of being able to deliver nuclear warheads across great distances including to the continental US.
The real question becomes how badly does the US want to stop North Korea from developing an intercontinental nuclear weapon that could could hit Los Angeles?
Would the North use that new power to deter the US while it bullied the South or even tried to take it over? Opinions vary wildly on this. Kelly, who says he's no dove on North Korea, believes the nukes are more for defence and says there is no way the basket-case north could try and take over the south.
Graham by contrast has a bleaker view of the North's intent, saying Kim might use his new power to coerce the South and drive the US out altogether.
Which position is right determines whether it might be better to act sooner rather than later whatever the consequences. US senator Lindsey Graham for instance – an influential voice on security matters in Washington – is an advocate of acting sooner rather than later.
If not, the US might despite all its rhetoric just have to live with a nuclear Korea.
"The Pentagon's been thinking about this for years," Kelly said, in explaining why the US should abandon talk of military action. "There are people way smarter than me who've thought all of this through to 50 steps. They know it all ends badly.”