On April 27, Kim Jong Un stepped over the military demarcation line at the Demilitarized Zone, becoming the first North Korean leader to set foot in South Korea since the war. Kim and his South Korean counterpart, Moon Jae-in, then joined hands and briefly crossed back into North Korea. Their subsequent summit was the first between leaders of the North and South in more than a decade and only the third ever. Historic symbolism aside, this is familiar territory for Korea. Since 1972, on both sides of the 38th parallel, reunification has officially been portrayed as a matter of when, not if. And occasionally, peace initiatives have edged beyond mere rhetoric, leading to vague plans to establish some sort of loose confederation between the two.
But the overriding reality is that the two sides would have to defy myriad more immediate concerns and interests to achieve reunification. As a result, various peace initiatives have routinely devolved into disingenuous ploys (particularly by the North) to ease international pressure, please domestic constituencies, exact material concessions and vie for advantage in a 70-year zero-sum fight for peninsular supremacy. And there’s ample reason to doubt the North’s sincerity again. In all likelihood, Kim’s outreach this year is in pursuit of some combination of staving off a war with the Americans, driving a wedge between the U.S. and South Korea, easing sanctions pressure and stalling for time to overcome technical hurdles to the development of a reliable long-range nuclear deterrent. Already, the North is for all intents and purposes a nuclear power, and it’s keen to see how this power translates into diplomatic leverage, as well as to demonstrate that it can be trusted to act rationally with the bomb.
Still, the dogged optimism from both sides isn’t empty gesturing. However strong the forces keeping them apart, both sides have a geopolitical imperative to reunify. As it stands, Korea is vulnerable to much stronger powers on its periphery (and ones that have historically used the peninsula as a steppingstone to attack each other), overly dependent on fickle allies, economically stunted and too fixated on the threats from across the DMZ to throw much weight around abroad. As one, they would become one of East Asia’s strongest military powers and obtain a freedom of action that hasn’t been seen on the peninsula in centuries. This has been true since the Korean War, but regional changes – most important, a rising China and a remilitarizing Japan – are only heightening this imperative.
Countries never fully achieve their geopolitical imperatives – the requirements of securing a nation in all its dimensions. But neither can they ever be fully ignored. Over time, whether or not they are acknowledged by those in power, imperatives remain the core of any country’s national strategy, surviving the fickle currents of more immediate geopolitical concerns that can dominate a state’s short-term decision-making. Thus, the two Koreas will continue to try to reconcile, even if the failures pile up. The more sincere this pursuit, the more dramatic the implications for the East Asian geopolitical landscape.
This Deep Dive examines the complicated reality of Korea’s unification dream. For the sake of better understanding what Seoul and Pyongyang have in mind as they try to build on their nascent detente, it focuses solely on the scenario of peaceful, negotiated reunification – not one involving the implosion of the North Korean regime, nor a collapse brought about by a U.S.-led military operation, nor a forceful takeover by either side. It concludes that although a largely symbolic confederation may be achievable, the odds are stacked against a truly meaningful reunification – that which Korea’s imperatives dictate it must pursue to be substantially better equipped to deal with the challenges rising outside the peninsula.
Why It Must Happen
For as much as Seoul and Pyongyang are fixated on the threat they pose to each other, historically, the threats to Korea have come from outside powers. The Korean Peninsula juts southward from Manchuria and eastern Russia, with the Yellow Sea to its west and the Sea of Japan to its east. Thus, historically, the peninsula has posed a potential threat to three major powers, regardless of the intentions of its government. Korea has always been a critical piece in any Chinese or Japanese strategy as a result. From the Chinese point of view, Korea served as Japan’s onramp to mainland Asia. When the peninsula was in Japanese hands, Manchuria and the Russian maritime regions, including Vladivostok, were threatened. From Tokyo’s perspective, if a hostile power were to hold Korea and thereby gain access to the Sea of Japan, it could threaten maritime trade and open the door to invasions of the home islands from the west and east. The result is that the peninsula has been invaded repeatedly – by the Mongols, Manchus, Chinese and Japanese, as well as by the Soviet Union at the end of World War II and the United States in 1950. These invasions were driven primarily by the peninsula’s value in attacking or blocking major powers.
Still today, Koreans see the peninsula as “a minnow among whales” – and the whales are getting hungry. China is flexing its newfound might, both military and economic, and pushing to reshape the region. Japan, which occupied Korea from 1910 until its defeat in World War II, is gradually remilitarizing and coming to terms with its need to take more responsibility for its own geopolitical imperatives. And the continued division of the peninsula is keeping it weak. The North is still looking for its economic footing following the loss of its core benefactor, the Soviet Union, whose collapse left Pyongyang overly dependent on Beijing and perpetually at risk of coercion. It has demonstrated an extraordinary talent for regime preservation during a period marked by famine and extreme poverty, but it nonetheless is perpetually at risk of major internal destabilization. The South’s concomitant surge of prosperity has only heightened this risk, while making forced reunification by the North increasingly a pipe dream.
The South, meanwhile, is again feeling the claustrophobic constraints of its alliance with the U.S., which has proved itself a fickle friend. The U.S. has mulled withdrawing from the peninsula repeatedly since the late 1970s, including reportedly during the Trump administration, which also happens to be contemplating a war against the North that would put the South at risk of devastation by North Korean conventional armaments. This can’t be ruled out, despite Seoul’s success so far in talking the Americans down. Even if the U.S. holds its fire, Seoul has ample reason to believe Washington won’t subsume U.S. interests to the South’s in a crisis. Seoul does not want to find itself in this position again.
A unified Korea would eventually be much more powerful, by most metrics, and in much better position to shape its own destiny and put an end to its legacy of foreign subjugation. Today, the two sides have 1.75 million troops, which if combined would be the world’s fourth-largest army. (Presumably, both sides would be able to scale down their forces dramatically, but they have demonstrated the capacity for an incredibly powerful military.) It would no longer have to devote an inordinate amount of resources to defending the DMZ and could reorient its force posture to external defense. It could conceivably emerge as a nuclear power. The U.S. would likely lose interest in military action, and thus lose the cause for keeping U.S. forces on the peninsula. China, Japan and Russia would face an ascendant and increasingly outward-focused neighbor. Over time (despite staggering initial costs), reunification could also dramatically boost the peninsula’s economic heft, with North Korean minerals and cheap labor flowing south, and South Korean technology, capital and food flowing north.
Why It Won’t Happen Quickly, If At All
It has made geopolitical sense since their establishment in 1948 for the two Koreas to find a way to get along and tap into their joint potential, and yet they haven’t, because peaceful reunification is exceedingly difficult to achieve. The North and South have fundamentally diametric economic and political systems and national ideologies. They also have very large guns pointed at each other’s head. Neither side has much reason to trust the other to refrain from trying to exploit the chaos that would come with a transition and force reunification on their own terms. This trust gap is not going away, nor is the prisoner’s dilemma. True reunification would require breathtaking courage from leaders on both sides, who would need to ignore immediate incentives and assume enormous risk while going through the process.
This is, in part, why only two modern states have achieved negotiated, peaceful reunification. One was Yemen in 1990, and its experience ever since has been nothing anyone wants to replicate. The more instructive comparison is Germany, which reunified the same year. Prior to being sliced in two by outside powers, both Germany and Korea were cohesive cultural, linguistic and ethnic entities. Yet both became locked in a protracted zero-sum contest for supremacy between their competing halves. Both are surrounded by countries that, through the long-term lens of their own geopolitical imperatives, would rather see them stay divided. Both had U.S. troops stationed on half their home soil. And like the North, East Germany suffered greatly from the loss of Soviet aid and security.
In most ways, though, the two Germanys were much better suited for reunification. By 1991, they were far more integrated than the Koreas are today, and the East was already beginning to disintegrate. East Germany had never adopted North Korea’s extreme version of totalitarianism and collectivism, and it didn’t derive its legitimacy from as intense a narrative of permanent siege by outside forces. The economic disparities between the two Koreas are also far wider. By 1991, West Germans were two to three times as wealthy as their eastern brethren, while South Koreans are estimated to be between 12 and 40 times richer than North Koreans (the North’s opacity explains the wide range in estimates). Thus, reunification was considerably less taxing for the West than it would be for the South, which likely wouldn’t enjoy the same level of outside funding for the process that the West Germans did. Despite their age-old suspicion of a united Germany, neighboring powers like France and the United Kingdom accepted reunification in service of the broader project of European integration, with NATO and the common market diminishing the threat of German domination of the Continent. None of Korea’s neighbors have a similar cause to tolerate a process that puts a more powerful state on their doorstep.
North Korea, despite its poverty, has already proved capable of surviving without Soviet support. And though Pyongyang does not want to be beholden to Chinese patronage, this lifeline isn’t going to dry up anytime soon, given China’s ascendancy and interest in retaining the North as a buffer state. As a result, North Korea is more likely to be able to hold out on reunification if it doesn’t like the terms. By comparison, West Germany and its allies were able to gradually entice the East Germans away from the wheezing USSR, which couldn’t afford to keep up heavy subsidies to its client states anyway. For all intents and purposes, West Germany absorbed East Germany. North Korea won’t willingly follow suit. And unlike East Germany, North Korea has nukes.
In short, there’s no template for the Koreas to follow. With so many unknowns and risks, Seoul and Pyongyang would have to start with some sort of loose confederation that enabled both sides to maintain their existing political and economic systems. (In fact, the first inter-Korean summit was intended to be held in the mid-1990s to discuss steps toward a confederation, but the death of North Korean founder Kim Il Sung in 1994 derailed the process and delayed the summit for another six years.) This structure could help weaken distrust between the two while creating mutual economic dependencies that raise the cost of abandoning the reunification process. But the path of least resistance is to delay decisions on the thorniest issues – and to date, most reunification plans made public, invariably short on details, could be best characterized as doing exactly that. And the path of least resistance won’t serve Korea’s imperatives. For a Korean confederation to be much more than a symbolic arrangement, the two sides would have to take on an inevitably messy and protracted process, vulnerable to innumerable political, economic and security-related headwinds.
The Problem of Two Militaries
The riskiest and most complicated challenge to meaningful reunification would be permanently backing off war footing and, eventually, merging the two militaries. This is also the most important step for the Koreas to be more than discrete countries in everything but name. If the goal is to become a unified power capable of executing a common strategy and keeping regional challengers at bay, Korea simply can’t have divided forces and parallel command structures that distrust each other. A de facto military alliance wouldn’t be enough, since any such arrangement would be fragile at best, beset with mutual suspicion and ripe for external exploitation. In that scenario, the two sides would have to continue to devote the bulk of their resources to deterring each other.
Eventually, the two sides would have to demilitarize the border, eject the Americans and find a way to lessen the threat they pose to each other without mutually disarming or demobilizing (a common step in many peace processes), since a unified Korea would still need a robust military. There is no easy way to do this that wouldn’t make one side vulnerable to an attempt by the other to break the detente and try to impose reunification on its own terms – and neither side is likely to weaken itself substantially as a show of good faith. In other words, for the North, pulling back its artillery from within range of Seoul would eliminate its biggest deterrent against aggression. For the time being, at least, the same limit applies to the departure of U.S. forces. Even if they could achieve these initial steps, both sides would still have the firepower to rain considerable pain on the other. The South’s capacity to conduct a decapitation strike against the Kim regime will never be abandoned, for example. Meanwhile, there’s still the thorny issue of the North’s nuclear stockpile.
To ease suspicions and create enough mutual incentives to keep momentum going toward reunification, a joint force would need to be established. This would also be needed to address the nuclear issue, assuming the North doesn’t just hand its nukes over to Trump when they meet – and assuming the South would be willing to incur the diplomatic and economic costs of going nuclear. These steps would face their own complications, from reluctance to hand over military secrets, to heightened coup risks, to crippling bureaucratic turf battles that would erode the readiness of the joint force. Again, there would be enormous incentives to cheat. Moreover, merging the military without merging the government would be problematic to say the least and would make it nearly impossible to craft or execute a common strategy. There is some precedent for effective joint command structures serving different governments. Washington and Seoul share command of the South Korean military, for example, but this was never intended to be a permanent solution, and either side could go it alone if it so choose.
The Problem of Politics
More than anything, the North Korean regime is hellbent on survival. This is why it wants nukes, and it’s why it remains so closed off to the world. And though reunification would certainly be a major economic boon in the North, potentially lessening agitation among the impoverished masses, it would threaten the regime’s grip on power in other ways.
The regime has survived war, famine and the loss of external support by sustaining an Orwellian reign of terror, putting the country on permanent war footing and conditioning the public to believe that the Kim dynasty is the only thing keeping the North from annihilation by outsiders (who are to blame for its internal woes). Entering into a union with the South, particularly if U.S. forces departed, would dramatically undercut Pyongyang’s siege narrative and cast doubt on whether the North Korean system was still necessary. Opening the economy to outside forces would spark a scramble for wealth among North Korean elites and allow competing power centers to proliferate. Meanwhile, the small steps that could be achieved with even a loose, mostly symbolic confederation – more joint exchanges, looser travel restrictions across the DMZ, expanded joint economic ventures and so forth – would expose more North Koreans to the South’s prosperity and discredit the regime by putting its economic track record in an exceedingly harsh light. Most risky for the North, bilateral military cooperation would weaken solidarity among the North’s forces, threatening the Kim dynasty from within.
East Germany intended to carefully control the reunification process once it tore down the Berlin Wall and other parts of the Iron Curtain in 1989. But things quickly took on a life of their own. East Germans (and the East German capital) headed west in droves, and within a year the government in East Berlin collapsed. Pyongyang cannot deliver the full benefits of reunification to the North and preserve its total authority. However tightly it may think it can manage the process, things are liable to get quickly out of hand.
In the South, meanwhile, public interest in reunification has declined over time as the costs of the process have become more apparent. Economically, despite the potential for massive long-term gains, reunification would be exceedingly problematic initially, with the South effectively forced to subsidize the North for decades even in a scenario that doesn’t result in regime collapse and, say, a southward flood of refugees. To prevent the disparities from sowing social chaos in the North, and to create a prosperous Korea capable of standing as one, northern institutions would need to be rebuilt from the ground up, northern industries subsidized and social safety nets extended across the 38th parallel. Total cost estimates vary widely, but even conservative ones exceed $1 trillion. (West Germany is estimated to have spent about twice that figure. Still today, Germans pay a “solidarity surcharge” tax of up to 5.5 percent to fund reunification.)
This reality has weighed on even the most dovish governments in Seoul, such as those in the 1990s led by Moon’s liberal mentors, former Presidents Kim Dae-jung and Roh Moo-hyun. Their “Sunshine Policy” of unconditional engagement with Pyongyang called for an “extended soft landing,” deeming immediate reunification impractical and instead focusing on preparing future generations for the process. In other words, it too kicked the can down the road. At the time, the rocky transition in Germany had served as something of a wake-up call in South Korea for how any transition is likely to defy the two governments’ best-laid plans. Since then, memories of what was lost with the division of Korea have faded only further, while younger generations of South Koreans have grown up amid remarkable prosperity, forced to pay attention to the North only when it lashes out. (This is, in part, why successive governments in Seoul have worked so hard to cultivate the narrative that Korean reunification is Korea’s glorious destiny.)
Meaningful reunification would take decades, meaning it would be warped by numerous campaign seasons in the South (and, potentially, the extraordinary uncertainty that would come with the passing of Kim Jong Un). Political resistance would become more pronounced if and when things got messy.
The Problem of Outside Powers
The country with the most at stake in Korea is China. Pyongyang isn’t as useful an ally to Beijing as it once was, and China would benefit from being able to expand its infrastructure and business networks across the peninsula, uninterrupted by the DMZ. More important, it may be able to stomach reunification if it meant an end to the U.S.-South Korea alliance.
Nonetheless, it prefers to have a weak and somewhat dependent neighbor over a larger, more powerful one, and the North’s survival as an independent state – with a substantial military and regime hostile to the U.S. and South Korea – remains important to protect China’s periphery. Beijing certainly cannot tolerate the unlikely but not wholly impossible scenario that unification returns U.S. forces to the Yalu River, and it would face a destabilizing flood of refugees if reunification spun out of control. Moreover, the North has proved useful in deflecting the United States’ attention and increasing U.S. dependence on China’s unmatched ability to manage Pyongyang. From this perspective, China wants to preserve North Korea exactly as it is. So regardless of how strange and unpredictable North Korea is, the Chinese will do what they can to prevent Korean reunification and maintain the current character of the regime.
Japan, meanwhile, benefits from the division of the Korean Peninsula to the extent that it keeps both the North and the South weak and focused largely on each other. Japan could also conceivably benefit from a strong, reunified Korea so long as the new state remained committed to the U.S.-led alliance structure, thus potentially serving as a substantial check on China.
What Japan cannot tolerate is a belligerent reunified Korean Peninsula that gets pulled firmly into China’s orbit, however unlikely this may be. Given its location offshore and its ability to threaten Korea’s export lanes, Japan would be a greater security threat to Korea than vice versa. This, combined with Korean memories of centuries of Japanese imperialism on the peninsula, means Tokyo can’t be sure that a united Korea would be friendly. If the U.S. remains committed to a trilateral security architecture in Northeast Asia, however, it would likely deter Japan’s least-favored outcome. Japan won’t always be so ill-equipped to shape regional events in its favor. But now, it’s left hoping that the U.S. will shape them on its behalf.
The U.S. certainly could do so – and make any discussion of peaceful reunification moot – by launching a war against the North. Its foremost strategic imperative on the peninsula is to prevent the proliferation of nuclear weapons, so its support for reunification would depend first on whether denuclearization actually could be achieved. Beyond nonproliferation, the United States’ prime concern is maintaining a regional balance of power, and South Korea is an important check on Chinese power.
Given its position in Japan, the U.S. could tolerate a withdrawal of U.S. forces from the peninsula, so long as it didn’t put Seoul at risk. It could tolerate reunification, depending on its form: a strong and united Korea threatens the U.S. only if it has nukes and the ability to strike U.S. shores. But like Japan, the U.S. doesn’t want to risk a northern-dominated Korea that falls firmly into the Chinese orbit, even if a unified Korea strong enough to stand on its own makes this scenario somewhat unlikely.
Today, as historically, the fate of the Korean Peninsula is not only Seoul and Pyongyang’s to determine. None of the outside powers with a major interest in Korean affairs have an outright veto on reunification, but one could imagine many ways in which they could try to shape the process in their favor, if not try to thwart it outright if it moved in a direction that hurts their own interests. But then again, this is why the Koreas have an imperative to unite in the first place, however chaotic and destabilizing it may be to try.