One of the most commented upon elements of this year’s outreach effort toward North Korea is the possible drift in the US-South Korean alliance.

It has been widely noted that the US is tightly focused on nuclear weapons and missiles, seeking a narrow arms control deal. The US would clearly be happy if North Korea were to liberalise, but no one in the US or Europe or Japan really seems to believe that is likely. The US seems resigned to deal with the DPRK as it is: gangsterish, Orwellian, feudal.

Nuclear weapons add a new level of destructive capability to be sure. But the North has long had the ability to wreak widespread destruction on the South without nuclear weapons.

South Korea, by contrast, is pursuing a wide-front détente effort to bring North Korea in from the cold. Through engagement and interaction, the thinking goes, North Korea will moderate and improve its behaviour. Border incidents and invective will decline as South Korea proved itself a fellow Korean partner state rather than an adversary. This broad approach would obviate the US focus on nukes and missiles. If North Korea is a partner for peace and relations improve, then its nuclear weapons matter less.

Much of this distinction in approach flows from ideology.

Moon Jae-In is from the liberal Democratic Party, and the South Korean left has long favoured détente and engagement. The left believes US hostility towards North Korea – placing it on the "axis of evil", for example – drives Northern paranoia. The South Korean left is also strongly nationalistic.

Unlike the South Korean right, which has sought better relations with Japan and the US, the left has long equivocated on which country – the US, North Korea, or Japan – is a greater threat to the South. So the North, for all its awfulness, is still seen as a potential partner.

Politically then, liberal governments simply worry less about the North's nuclear weapons. The South Korean left does not fear or believe that North Korea will use nuclear weapons against the ROK, a fellow Korean people. The North's nuclear weapons are intended to deter the US and, quietly, China. North Korea, in this framing, is an alienated twin, a brother Korean state artificially separated from its companion by the intervention of foreigners in the late 1940s.

There is, however, also a strategic reason for the low interest in nukes, one often unheard or unmentioned in the non-Korean press, where the assumption of a robust alliance suggests a shared threat perception of North Korea: for South Korea, the nuclear threat from the North is not really new. 

North Korea’s nuclear missiles give it the new ability to strike many other states: the US, China, Japan, Southeast Asia, and possibly as far as Australia and Europe. For them, a North Korean threat is new. I have attended meetings and conferences where even Australian officials have discussed missile defence.

South Korea, by contrast, has lived under direct North Korean threat for decades. Nuclear weapons add a new level of destructive capability, to be sure. But the North has long had the ability to wreak widespread destruction on the South without nuclear weapons.

The Korean peninsula is rather small and tightly packed. Its few cities are very dense. South Korea has also, in a colossal strategic error, placed its capital just thirty miles from the border and allowed it over the decades to swell and sprawl into a gargantuan metropolis of more than half the national population and economy. It is well established now that North Korea effectively holds Seoul hostage by pointing thousands, perhaps tens of thousands, of artillery and rockets at it.

So while North Korea could potentially use strategic nuclear weapons against Southern cities, North Korea already has a "city-busting capability" which makes its step up to nuclear capability less dramatic. Nuclear missiles do make it easier to hold South Korea’s cities south of Seoul hostage, as South Korea’s conservative newspapers routinely point out. But those cities are increasingly less important as South Korea’s extraordinary centralisation on Seoul – its evolution into a city-state like Singapore – continues.

In short, the leap in the strategic threat from a nuclear North Korea is substantially smaller for South than it is for all other states.

This is likely the main reason for US President Trump’s war threats and the general US hysteria over North Korean nuclearisation in 2017. The US homeland was suddenly reachable by the world’s scariest country. Striking the homeland is a relatively rare occurrence in American strategic history. Few states have ever had the ability to range the US mainland, and strikes on US territory have been extremely rare – Pearl Harbor and 9/11 are the most obvious.

It is occasionally suggested that North Korea might develop tactical nuclear weapons for use on the battlefield, to help compensate for the its inferiority in conventional weapons. Evidence of Northern battlefield weapons development will be taken as yet another red flag that the North is not serious about denuclearisation, but so far, North Korea has not taken this step. There is little evidence that North Korea sees nuclear weapons as war-winning weapons rather than for deterrence purposes. So again, for South Korea the North’s nuclearisation adds far less scary new potential than for many other states.

Finally, another little-discussed reason for the lesser interest in nuclear weapons, especially on the South Korean left, is the hope that the North’s nuclear weapons will fall into the hands of a unified Korean state. I have not seen this written up anywhere, but I have heard hints of this for years here in Korea.

If the left’s project of détente and reconciliation works, then it could well culminate in a two-systems-one-nation Korean confederation along the lines of China and Hong Kong. Certainly, the South Korean left has thrown around ideas for a confederal structure since the 1970s, and North Korea has broached this too. If such a confederation were to organically grow over time into a genuinely unified Korea, then the assets of the two Korean states would increasingly be shared. In time, that could mean that a unified Korea inherits the Northern nuclear program.

Given that the South Korean left does not see North Korea as an enemy, but harbours deep animosity for Japan and American intervention in South Korea life, a nuclearised, unified Korea would be an ideal foundation from which to pursue a neutralist, non-aligned, post-unification foreign policy.