For any number of foreign-policy pundits, nonproliferation zealots, late-night chatterbots and enterprising T-shirt vendors, the Donald Trump-Kim Jong-un feud has been the gift that keeps on giving career advancement.

Yet for all the debate over how to deal with North Korea's nuclear weapons, there are really only three options. The first, to which the vast majority of national security and military professionals are resigned, is remarkably unsatisfying: live with it. North Korea apparently already has a small arsenal of functioning warheads and its missile tests show an ability to reach the continental US It's too late to turn back the clock. Let's try to keep Kim in a box and focus on not getting into the same pickle with Iran. (Although some of us think that's inevitable as well.)

The second is to reinvent the wheel and come up with a form of statesmanship that will succeed where decades of other policies have not. Bill Clinton tried carrots (oil and aid). George W. Bush tried sticks (sanctions and opprobrium). Barack Obama tried something called “strategic patience,” which was as ineffective as it was rhetorically nonsensical. Donald Trump's approach, unsurprisingly, has been all over the place, but mostly centres on nasty tweets and undermining his own secretary of state.

To be fair, some people have been thinking outside the diplomatic box. Last week, this column featured eminent law professor and former White House staffer Philip Bobbitt, who argued that the US and China should cut a bilateral deal in which Beijing would take North Korea under its security umbrella in return for Kim putting his nuclear program in mothballs. Others call for revivifying the moribund six-nation talks, or for letting the North keep its fissile material but give up its long-range missiles, or a long term plan of “deterrence and gradual rollback.”

As for the third option — a military solution — it's been pretty much discarded as a nonstarter. Even if we somehow avoided a nuclear exchange, the damage to Seoul from North Korean artillery be would so vast as to render the idea unthinkable. Or would it?

This week I tracked down somebody who has actually been thinking quite a bit about it: retired Air Force General Merrill “Tony” McPeak. McPeak has the distinction of being the only person to have served as both Air Force chief of staff (from 1990 to 1994, during Operations Desert Storm and Desert Shield) and also as the service's acting secretary. Prior to that, he was commander of all Pacific air forces, so he knows a thing or two about what a “hard target” North Korea is. With a three-volume memoir of his military career finally completed, McPeak took time to share his contrarian views on how both diplomacy and hard power could finally break the logjam with the Kim Jong-un regime. Here is an edited version of our chat:

Tobin Harshaw: Tony, we first met in early 2003 in the run-up to the Iraq invasion, and there was a big debate at the time over whether airpower alone could win a war — remember Shock and Awe? You said something to the effect that that, yes, airpower could win wars, but the one place where it absolutely couldn't was North Korea. And I think we're learning that lesson again today, right?

Merrill McPeak: Well, I'm not sure I will give you the same answer today — airpower has changed a good bit in the last 15 or so years. We are much more precision-oriented now as far as munitions go.

The real problem that I had in the early 21st century was the guns that are dug in on the reverse slope of the hills just above the DMZ. There are thousands of them; they're on rails and they've got blast doors. They can run them into a cave, close the doors, load and cock, open the doors, run them out and shoot, run them back in. So they are tough targets to attack. And some subset of the whole actually ranges Seoul, which means millions of people and, what, two-thirds of the net worth of South Korea. So my concern was that Seoul would be very, very badly damaged in the opening minutes of any encounter.

Yet the advantage that those guns have — being in caves and protected by blast doors — it also has a big disadvantages. They're not mobile; other than a few feet to get in and out of a cave, they're not going anywhere. And they are at known positions. We know the coordinates of every gun. Nowadays, we can drop GPS-guided ordinance on coordinates with a miss-distance of just 10 meters. A 10-meter miss with a 2,000-pound conventional bomb means that gun is out of action, because the blast doors would cave in. The people inside will likely be out of commission for a while. This is a different kind of a threat to those guys.

I still think that in the opening moments of any aerial campaign against the North there will be some damage in Seoul, probably considerable. But I no longer think that you have to go in and take those guns out with ground forces. I think you could probably silence the guns pretty rapidly from the sky, especially those that range Seoul.

TH: Of course, those guns aren't the whole shooting match.

MM: Yes. In the meantime, you have to go after the nuclear infrastructure as a very high priority. And also you have to go after the command-and-control, including decapitating the major national command authority at Pyongyang. And I'm a little less confident about some of those targets because they are mobile. Kim himself is mobile. And the last rocket shots I saw from their nuclear program were mounted on mobile platforms. So we're going to depend on a lot of intelligence that has to be real-time, whereas the coordinates of these artillery pieces are not going to change.

TH: So what would taking out the nuclear-weapons infrastructure involve?

MM: It involves everything from beginning to end in their nuclear-munitions category and in the transportation category. The rocket-production infrastructure and the bomb-production infrastructure. That is a target set that is end-to-end attackable. Some of it may be deeply buried, which means you probably can't get at it, but you don't need to break every link in the chain, just enough that it stops production. You want to attack launch-pads, you want to attack the warehouses that the rockets are in, you want to attack the factories that are producing rockets, you want to attack them en route to a launch site.

So there's an end-to-end target chain that you can interrupt at any point and disable the whole system, but it depends on real-time intelligence, and to some degree that means intelligence that's not under Air Force control — a lot is CIA.

TH: Would this require things other than air power like Special Forces on the ground?

MM: No. Special Forces are really good, although a lot of times they get in trouble and then you've got to divert everything else you've got to save them. But I believe we can put together an air campaign that A) brings an end to the artillery threat to Seoul rather rapidly and B) disrupts and disables their nuclear-munitions delivery capability rather rapidly. And that can be done totally by air. I'm not talking about just US Air Force, but Navy air and Marine air — everybody has got an air force, the CIA has its own air force — so we are going to have to cooperate here.

TH: Assuming there is no nuclear exchange, is there any way of estimating how bad the damage to Seoul would probably be?

MM: I think it depends on how skilful we are at handling this problem. And that's a whole other thing, because we're not showing a lot of cleverness these days.

One idea would be to say to Kim, “OK, we are setting a deadline here” — say it's next January — “and by the end you will either be dismantling your nuclear capability under international inspection or we will help you dismantle it.” If you give that kind of deadline, in the meantime you continue all your diplomatic efforts, all your economic sanctions, the effort to get the Chinese and the Russians to help, and everything else. All the other instruments of national power need to be brought to bear on this problem before we resort to military attack.

If you set a date final by which we have to see a solution or we will intervene, then you've got time to try to minimise the damage to Seoul through defensive measures. Evacuate people, in the worst case. I think there's a real limit to how much you can do there. But you could do something. And then we need to really meticulously plan the attack on these artillery positions to make sure that they're as damaged as possible as quickly as possible. At the end of the day, we will get some damage, but it won't be Stalingrad. We've had fights like this before. We've had the Blitz in London. We've rebuilt Seoul before.

TH: During the Cold War, there was a cynical saying that the US was willing to fight the Soviets “down to the last German.” This could be seen as fighting Kim down to the last South Korean.

MM: For the US, the threat here is to Chicago and to New York City. We can't allow the North Korean government to get the capability to hold major American cities hostage. And if they don't have it already, they soon will.

TH: Throughout the Cold War we were able to live with the Soviet Union, in effect, holding our cities hostage in that same way. And we managed, through containment and deterrence, to wait them out. Why can't we live with a nuclear-armed North Korea?

MM: I think it's possible that we can. So you have to say, “Well, what are the odds that we can't, that he's not deterrable?”

We know there are non-state actors that are not deterrable, right? That's the definition of a suicide bomber. You can't deter him because he doesn't care — he's ready to give up on life entirely. And we don't know what category Kim is in. Let's say we think the odds are very good that he's deterrable — let's say 90 percent. So do we want to take a 10 percent risk on losing New York City?

TH: Are you looking for me to answer that? I'm the one who lives there.

MM: Hah. As I'm sure you know, the problem with deterrence is that the other guy has to have something at stake. Certainly we were able to live with Joseph Stalin. He had something to lose. Even Mao Zedong did. They didn't want to see Moscow and Beijing evaporated.

What does Kim Jong-un have to lose? I don't know. I think he'd probably rather live than die. He's not a suicide bomber in my opinion. But I don't know how to calculate the odds.

TH: So we have to err on the side of intervention?

MM: Look, we would be much safer as a country if the world contained zero nuclear weapons. They do not enhance our security. We have very superior conventional war-fighting capabilities, so we'd be much better off if nobody had nuclear weapons. Now, we're not going to get there — not least because Israel won't give up its weapons, and if even one country insists on keeping them, then we can't achieve a nuclear-free world.

So our problem is, what steps do we take to keep ourselves safe in a proliferating world? We've already made a huge mistake by not insisting that India and Pakistan stop their programmes. We have been lucky so far with Iran because Barack Obama was smart enough to give us a 10-year breathing period, which Donald Trump seems for some reason anxious to give away.

But here we have a case with North Korea that appears to me to represent more or less the classic case of when we should intervene pre-emptively. We have military forces precisely for a case like this, where someone who is unpredictable, maybe crazy, who executes his uncle with an anti-aircraft gun, and we have no reason to think that he's not fully capable of doing what he says he's going to do. He says he's got a red button — it may be smaller than Trump's, but he's got a red button, and we shouldn't allow that position to continue.

TH: You warned about proliferation. Do you think that allowing North Korea to continue to develop its arsenal would actually push Japan and South Korea towards building their own nukes?

MM: I don't know, but I think that if you can't stop North Korea, a poor nation with starving people, who can you stop? Why shouldn't Singapore want nuclear weapons?

TH: Let's get back to this potential military intervention and giving Kim a deadline to denuclearise. Of course, it's not just the US and North Korea that are involved here. Obviously South Korea, Japan and China are right there …

MM: And Russia's got a common border. People don't realise that — it's just a few kilometres of border, but Vladivostok is certainly more threatened than San Francisco.

TH: Exactly. How do you think those various parties would react to this idea?

MM: I don't know, in large part because I don't think we're handling ourselves very well in this regard. We should be working very closely with China. What Chinese interest is served by North Korea's possession of nuclear arms? Or Russia's? Our inability to work with the major powers on this issue more adroitly is one measure of how clumsy this administration has been.

TH: I agree that the Chinese should have no interest in a nuclearised North Korea. But they've certainly not done everything they can to keep it from happening.

MM: Nor have we. We took our nuclear weapons off of the peninsula decades ago. We used to have tactical nuclear munitions there. When I was commander of the Pacific air forces, those weapons were under my supervision. And there are a lot of other steps that we could take with North Korea right now towards a peaceful resolution. We could officially end the war. The current armistice is not a peace agreement. I'm sure the North would love it.

On the economic side, we could lift the embargo. When I was on the Joint Chiefs of Staff we were saddled up to do something about Korea. And Jimmy Carter went up there and negotiated an agreement under which we were supposed to provide fuel oil and they wouldn't have to build nuclear power plants. But we let that come apart largely because of maladroitness on our side.

We could even take our forces off the peninsula. From my point of view, that's a negotiating point.

TH: Honestly?

MM: I'd rather do that than watch San Francisco evaporate.

So there are plenty of steps that we could take in a negotiation, and we ought to make it clear to Beijing that we do have this kind of flexibility. And if that won't convince them to help, then nothing will, and we'll simply have to do this militarily on our own.

TH: You spoke favourably just now about the Iran nuclear deal. If we did go ahead and “dismantle” the North Korean programme, how do you think the Iranians would react to that? My concern would be that they would drop out of the deal and try and build up their own arsenal as quickly as possible.

MM: I don't know why that would happen. If they saw that we were serious about stopping nuclear proliferation, why would that give them an incentive to proliferate? I would think it would be just the reverse — that they would say, “OK, maybe these guys are adults, serious enough to do serious work.”

TH: What I mean is that under the deal, they able to build their own program after it sunsets. But I think they would no longer be able to trust that would happen if they saw us stop at nothing to get rid of the North Korean arsenal.

MM: Well, frankly, I think it's a bigger question whether you can trust this administration in any respect. Pulling out of Nafta and the Pacific trade negotiations and the Paris accords on global warming and so on. So you just say to yourself: Well are these guys good negotiating partners or not?

TH: So do you think the Iranians can just wait out Trump?

MM: I don't see what Iranian purpose is served by not waiting.

It's a 10-year deal. Now it's clear that on our side we want to extend it forever. It doesn't work for us to let them have a large stock of nuclear weapons starting 10 years from now. So we would like to negotiate a nuclear-free Persian Gulf zone and get everybody to agree to it. Now Israel, as I say, would never come into that. But maybe you could get Iraq, Iran, Saudi Arabia, Qatar and everybody else to shake hands and say, OK, if we have a fight, we'll do it with conventional weapons.

North Korea – South Korea relations: in pictures Show all 21 1 /21 North Korea – South Korea relations: in pictures North Korea – South Korea relations: in pictures Pukguksong-2 missile - 2 May 2017 A solid-fuel "Pukguksong-2" missile lifts off during its launch test in North Korea on May 22, 2017. They said that it was examining operational plans for attacking Guam, an angry reaction to UN punishment for previous North Korean intercontinental ballistic missile tests and a US suggestion about preparations for possible preventive attacks to stop the North's nuclear weapons program. Korean Central News Agency/Korea News Service via AP North Korea – South Korea relations: in pictures Hwasong-12 -16 September 2017 North Korean leader Kim Jong-Un inspecting a launching drill of the medium-and-long range strategic ballistic rocket Hwasong-12 at an undisclosed location. Kim vowed to complete North Korea's nuclear force despite sanctions, saying the final goal of his country's weapons development is "equilibrium of real force" with the United States, state media reported on September 16, 2017. AFP/Getty Images North Korea – South Korea relations: in pictures Donald Trump address South Korean assembly - 7 November 2017 President Donald Trump talks with South Korean President Moon Jae-In during their joint press conference at the presidential Blue House on November 7, 2017 in Seoul.Trump was the first US President to address the South Korean National Assembly since President Clinton in 1993. He addressed Kim Jong Un warning him to not underestimate the US and that for talks to materialize then Pyongyang would need to take steps into denuclearization. Getty North Korea – South Korea relations: in pictures Demilitarized Zone Haean-Myeon, is a small military town near the Demilitarized Zone (DMZ) and border between North and South Korea, in Gangwon province. The zone is a strip of land running across the Korean Peninsula and was created after the 'Korean Armistice Agreement'. Any negotiations between the two countries tend to take place in this zone. AFP/Getty Images North Korea – South Korea relations: in pictures Declared state sponsor of terrorism by Trump - 20 November 2017 President Donald Trump speaks to the media during a cabinet meeting at the White House on November 20, 2017, where he officially designated North Korea as a state sponsor of terrorism. North Korea had previously been on the list, however was removed in 2008. Getty North Korea – South Korea relations: in pictures Hwasong-15 intercontinental ballistic missile - 29 November 2017 The North Korean government launches it's Hwasong-15 intercontinental ballistic missile at an undisclosed location in North Korea on November 29, 2017. It is supposedly capable of reaching all parts of the US. Korean Central News Agency via AP North Korea – South Korea relations: in pictures Hwasong-15 intercontinental ballistic missile - 29 November 2017 North Korean leader Kim Jong-Un celebrating the launch of the Hwasong-15 missile on November 29, 2017. AFP/Getty North Korea – South Korea relations: in pictures Kim Jong-Un New Year's speech - 1 January 2018 North Korean leader Kim Jong-Un delivering his New Year's speech. He vowed North Korea would mass-produce nuclear warheads and missiles in a defiant New Year message on January 1 suggesting he would continue to accelerate a rogue weapons programme that has stoked international tensions. Korean Central News Agency via AFP/Getty North Korea – South Korea relations: in pictures Intercontinental ballistic missile ice sculpture - 1 January 2018 Fireworks are seen above the Taedong River during New Year celebrations as visitors pose for a photo in front of an ice sculpture of an intercontinental ballistic missile at the Pyongyang Ice Sculpture Festival in Kim Il Sung Square in North Korea on 1 January, 2018. REUTERS North Korea – South Korea relations: in pictures US-South Korean military drills postponed - 4 January 2018 South Korean President Moon Jae-in talks with US President Donald Trump on January 4, 2018 in Seoul. South Korea and US agreed to delay the annual "Foal Eagle" military drills until after the PyeongChang Winter Olympic Games in an effort to "de-conflict" the Games and "focus on ensuring the security" of the event. South Korean Presidential Blue House via Getty North Korea – South Korea relations: in pictures North and South Korea have first official talks in over two years - 9 January 2018 Vehicles transporting the South Korean delegation, led by South Korean Unification Ministrer Cho Myoung-Gyon, drive past a checkpoint on the road connecting South and North Korea at the Unification Bridge, near the Demilitarized zone (DMZ) separating them both on January 9, 2018 in Paju. They began their first official face-to-face talks in two years. Getty North Korea – South Korea relations: in pictures North and South Korea have first official talks in over two years - 9 January 2018 Members of the South Korea delegation (R) shake hands with members of the North Korean delegation (L) during their meeting at the border truce village of Panmunjom in the Demilitarized Zone (DMZ) dividing the two Koreas on January 9, 2018. They focused on the forthcoming Winter Olympics after months of tensions over Pyongyang's nuclear weapons programme. AFP/Getty North Korea – South Korea relations: in pictures Foreign Ministers Meeting on Security and Stability on the Korean Peninsula - 16 January 2018 Foreign Ministers from twenty countries from North and South America, Asia, and Europe pose for a photo at the Vancouver Foreign Ministers Meeting on Security and Stability on the Korean Peninsula, in Vancouver on January 16, 2018. The US urged an escalation in pressure on North Korea over its nuclear missile program, despite a more cautious tone from key US ally South Korea. Secretary of State Rex Tillerson, co-hosted the event with Canada's foreign minister Chrystia Freeland, and called for North Korean ships to be intercepted and for new punitive measures to be implemented every time Pyongyang tests new weapons. AFP/Getty North Korea – South Korea relations: in pictures North Korea and South Korea to march together at Winter Olympics - 20 January 2018 PyeongChang 2018 Olympics President Lee Hee-beom, North Korea's Sports Minister and Olympic Committee president Kim Il Guk, International Olympic Committee President Thomas Bach, South Korean Minister of Culture, Sports and Tourism Do Jong-hwan and South Korea's National Olympic Committee President Lee Kee-heung join their hands as they pose during a signing ceremony at the Olympic Museum on January 20, 2018 in Lausanne. North Korea will send 22 athletes to the Winter Games in the South. The two nations will also march together at the opening ceremony. AFP/Getty North Korea – South Korea relations: in pictures Anti-North Korea activists protest delegation arrival - 22 January 2018 Anti-North Korea activists burn a portrait of leader Kim Jong-Un during a rally Seoul Station as a North Korean delegation arrived to check out performance venues for the Winter Olympics on January 22, 2018. Protesters led by the Korean Patriots Party gathered and complained that the talks to encourage North Korea's participation is stealing the spotlight from their country to the benefit of the regime. Donga Daily via Getty North Korea – South Korea relations: in pictures Panmunjom - 7 February 2018 South Korean soldiers stand guard at the border village of Panmunjom in the Demilitarized Zone (DMZ) between South and North Korea on February 7, 2018. In a sign of thawing bilateral ties, North Korea today announced that Kim Yo-jong, the sister of North Korean leader, Kim Jong-un, will attend the opening ceremony of the PyeongChang Winter Olympic Games. Getty Images North Korea – South Korea relations: in pictures North Korean ferry arrives in South Korea - 6 February 2018 North Korean ferry Mangyongbong-92 carrying a 140-strong orchestra approaches a port in Donghae, South Korea, February 6, 2018. REUTERS North Korea – South Korea relations: in pictures Anti-North Korea protest - 6 February 2018 A member of a conservative civic group tears a portrait of North Korean leader Kim Jong Un during an anti-North Korea protest as the North Korean ferry Mangyongbong-92 carrying a 140-strong orchestra approached. REUTERS North Korea – South Korea relations: in pictures North Korea at the athletes village - 8 February 2018 A North Korean flag is seen hanging on a building at the Winter Olympics athletes village in Gangneung, South Korea. REUTERS North Korea – South Korea relations: in pictures Olympic Welcome ceremony - 8 February 2018 Democratic People's Republic of Korea Vice Sports Minister Won Gil-woo receives a gift from mayor of the Olympic Village Kim Ki-hoon during the welcome ceremony ahead of the PyeongChang 2018 Games at the Olympic Village on 8 February, 2018 in South Korea. Getty Images North Korea – South Korea relations: in pictures Mike Pence meets Moon Jae-in - 8 February 2018 US Vice President Mike Pence shakes hands with South Korean President Moon Jae-in before their meeting at the presidential office in Seoul, South Korea on 8 February, 2018. REUTERS

Again, it's a mystery to me why people want nuclear weapons. They think it gives them a voice at the table I suppose. But it's subversive. It eventually will end in disaster. I think everybody knows that. And the more people that have nuclear weapons, the sooner we'll end in disaster. I don't believe in nuclear winters and stuff like that, but it would be a game-changer in the history of humankind if we go to the mat with nuclear weapons. People ought to just understand that and do something else.

TH: I don't think I agree in terms of the lessons learned so far. Obviously Israel, which we believe has nuclear weapons, has been able to maintain its security in a rough neighbourhood. India and Pakistan, neither of which needs nuclear weapons, have not been punished by the international community for having them. I don't think it's ended poorly for anyone yet.

MM: It ended poorly for the Japanese. It's just hard for me to see an upside to a nuclear-armed world. We’ve gotten through it so far. Breathe a deep sigh of relief. The doomsday clock stopped inside five minutes to midnight. But I don't know how often we can go to the brink — how many Cuban Missile Crises we have to have before somebody really does go crazy.