The end of a 60-year conflict; the elimination of one of the gravest threats to world peace; a high-speed rail link from Seoul to Helsinki. The reunification of the two Koreas would have enormous implications, not only in Northeast Asia but throughout the world.

It would be no easy task though. Over the next four pages, we explore the challenges faced by reuniting one of the world’s poorest, most belligerent and outright strange nations with one of the most modern. From predicting who the new heroes of a united Korea will be, to outlining the chances of putting Kim Jong-il on trial – with a few lessons from Germany’s reunification two decades ago and the view from the world’s major capitals – this is Monocle’s guide to how Korea could, once again, unite.

Few drastic geopolitical events seem as inevitable as the reunification of the two Koreas. Everyone knows why – the sovereignty of an isolated, hungry, totalitarian North looks unsustainable – but when and how it will happen remains uncertain. Throughout the 1990s, as the Cold War ended and Germany presented a model of relatively easy and successful integration, a Korean echo looked imminent, but never arrived.

Still, the German-style model of absorption where the successful South swallows the impoverished North, is the most likely scenario. But strategists wonder what could finally provide the push for Pyongyang to retreat from what officials there have portrayed as an existential ideological standoff. A scrum for control in the wake of Kim Jong-il’s death could start things off – perhaps pitting communist party factions against army generals – and prompt the country’s overdeveloped defence industry to quiver.

Signs of instability or governmental weakness could also inspire citizens to make economic demands that Pyongyang cannot meet. A condition of aid rescue from South Korea or the international community could be accepting a reunification plan. Seoul would effectively bail out the failed state, assuming what could be a multi-trillion dollar cost to integrate the two countries.

But there are also reasons to believe that peaceful German-style absorption might not be a certain outcome on the Korean peninsula, where tensions (since a deadly civil war) are much stronger and the gap between life in the two countries is far more vast. The surprisingly hardy North Korean regime has survived a transition of power from Kim Il-sung and a massive famine, and leans towards provocation rather than reconciliation.

Foreign uncertainties about the North’s military capacity and the nuclear risk involved mean that small incidents can easily escalate. A naval exercise or demilitarised zone clash could trigger a spiralling conflict that draws in the US and China (which WikiLeaks reveals has already countenanced a united Korea). Those armies could also find themselves marching on Pyongyang under other circumstances: as part of an international coalition invading in a last-ditch effort to contain Pyongyang’s arsenal or to settle internal unrest. Then reunification becomes a term of negotiation at war’s end.

One scenario lingers that requires no shots fired, no protests. What if Kim Jong-un, the twentysomething Swiss boarding-school alumnus and North Korean heir apparent, turns out to be an eager moderniser? His regime could introduce market reforms that eventually open the North’s economy to foreign trade. Even without political reform, the two Koreas become mutually dependent partners, building a relationship that a RAND Institute study likened to the increased compatibility between China and Taiwan. With time, the two systems look more like one another, and the North enters an agreement to reunite.

The Korea Institute for National Unification, a Seoul thinktank, maintains a “Unification Clock” modelled on the nuclear doomsday timepieces popular during the Cold War. The institute surveys 51 experts and, depending on their collective judgment, sets the clock’s hands to reflect how far along they are to being one again: midnight represents reunification. For the agreement-type model, the clock today stands at 16.19. For absorption, it’s a few minutes before 18.00.

Germany’s reunification – sudden, dramatic, peaceful – took its leaders by surprise. Little planning had been made in Bonn before the Berlin Wall fell in November 1989.

In the months that followed, the combination of Helmut Kohl’s ambition and the vast weight of public opinion made unification inevitable, but too many decisions were improvised and too much hope was invested. Kohl famously promised East Germans “Blühende Landschaften” (blossoming landscapes). The harsh realities left a bitter aftertaste for many people.

“Two decades after reunification, euphoria has given way to normalcy and, Germans being Germans, this means a degree of sobriety and melancholy,” says Dr Leonard Novy, a fellow at the Berlin-based thinktank Stiftung Neue Verantwortung. While support for a united Germany remains high, there is widespread consensus that bringing together vastly different economies and societies proved far more difficult than expected.

“Policy choices made under the dramatic circumstances of the fall of the Iron Curtain in 1989-90 effectively equalled a sudden absorption of East Germany into the West,” says Novy. “This soon came to be perceived by many Easterners as a colonisation process driven by the West’s political and economic elites.”

On the one hand the difference between East and West Germany does not mean a lot to the younger generation any more. Usually people will not be able to tell whether TV hosts or pop stars are from Munich or Dresden. But this cultural convergence is in contrast to the economic situation of the country. Wages in the East are still lower, growth rates trail behind and unemployment continues to be higher than in the West.

“Despite the fact that overall the peaceful unification of the two Germanies must be seen as a resounding success, the Wall still casts its shadows,” says Novy.

The German experience – a breathtakingly rapid reunification at significant costs – supports the argument for a more gradual process in Korea.

The four non-Korean countries in the six-party talks are intent on finding a solution to the roiling concern over the North’s nuclear ambitions. Unification would almost certainly resolve the crisis – Kim Jong-il and his generals would not have their hands on the nuclear button in a united Korea – but for all the members of the quartet, unification may simply create new challenges and threats.

Japan would be pleased to see the end of North Korea and the missiles that are aimed in its direction. But if the peninsula finds its identity after unification by indulging in a new Korean nationalism, Japan – still litigating aspects of its own imperial occupation – will find itself a fresh target. And if Pyongyang’s nuclear programme is as far advanced as it claims, and the unified country refused to dismantle it, Japan could find itself as the only non-nuclear power in the region.

When it comes to the US, a more stable Korean peninsula could lead to a diminished role in northeast Asia. US forces stationed in South Korea are already unpopular among the locals who see the superpower’s footprint as an uninvited imposition. And a removal of Pyongyang’s menace would leave Seoul with even fewer reasons to welcome a large American military presence. China, too, would be unlikely to agree to the presence of US troops in a country right on its borders.

Given its economic reach and ­regional influence, Beijing is best positioned to play a strong hand in its neighbour’s affairs but even here there are potential pitfalls. If unification is triggered by war or internal chaos, China’s cities could be overwhelmed by new refugees, and an ongoing rebuilding effort in North Korea could redirect some of the foreign investment currently flowing to China.

Russia’s strategy for the region has been propelled by its commercial interests and it might get the most immediate gift from reunification: a new border with a major economic power with whom it has had growing trade ties. Moscow is already working on an oil and gas pipeline into Korea and will work on connecting North Korean trains to the trans-Siberian line.

Unification would also be a test for the UN. One scenario currently under consideration at the UN is to run the North as a protectorate if the Kim regime falls before handing it over to the South once its economy had been revived. Given the difficulties the UN has experienced with nation-building in the past – even tiny Timor-Leste was a challenge – such a task is unlikely to be straightforward.

Whether as architects of a new nation or as members of the cultural advance party, the fortunes of these Koreans could swing momentously if North and South unite

At 42, the newly appointed boss of South Korea’s largest chaebol has a long career in front of him, and the opening of a big domestic market and workforce is an easy path to growth.

Other than Kim Jong-il, the “People’s Rooney” is the only North Korean known outside the country. Would he lose his global standing if he had to fight for a spot in a unified Korean side?

Kang made his name in 1994 with The Aquariums of Pyongyang, a memoir of his childhood in a labour camp. He could write the first great book about North Korea once archives are opened.

Park lost a campaign for South Korea’s presidency in 2007 but is a frontrunner for the office next year. If elected, the country’s first woman president could be a major player during unification.

Though not Korean, Kim Jong-il’s former sushi chef and author of a memoir has the CV and profile to become Pyongyang’s version of Nobu Matsuhisa.

The legacy of a murderous civil war, six decades of military confrontation and a rigidly enforced division: any truth and reconciliation process is potentially explosive. Moreover, it would be twofold: an inter-Korean process, and an intra-North Korean process to investigate Pyongyang’s gruesome human rights record.

However, most unification-based discussion in the South is economy-focused. Experts anticipate prioritisation of socio-political stability, thereby enabling economic development if – as expected – the South’s conglomerates parachute managerial teams in to kick-start the North’s economy.

“My guess is truth and reconciliation between the two Koreas will be subordinated to political expediency,” says Michael Breen, a biographer of Kim Jong-il. “The new authorities will not allow a process to paralyse the country.”

A precedent exists for maintaining extant power structures, such as the North’s army and party, to obviate decontrol: brutal figures from the colonial administration remained in power in South Korea after independence from Japan in 1945. (Their continued existence provided Kim Il-sung with one motive for 1950’s Korean War.)

Even South Korea – a vibrant democracy – last year disbanded its own Truth and Reconciliation Commission over sensitivities surrounding Korean War massacres and human rights abuses by Seoul’s authoritarian governments. But the scale of uncovered horrors in the North could be too great to ignore. “I am not very optimistic,” sighed Dr Kim Sung-soo, a former official of the commission, when asked about post-reunification reconciliation.

Q&A

Choi Jin-wook

Dr Choi Jin-wook, 52, has spent 18 years at the Korea Institute for National Unification thinktank, where he is director of North Korean studies.

What are the best and worst scenarios for reunification?
The worst: a war started by North Korea that initiates unification. The best: a North Korean regime change that leads to political transformation.

And the most likely scenario and timeframe?
Kim Jong-il dies; there is political or social conflict; North Korea adopts a Chinese-style “soft dictatorship”. We could then have reconciliation and reunification in 10 years – or permanent division.

Do South Koreans want reunification?
In polls, over 20 per cent say “No”. There is a gap between the old and the younger generations.

Reunification: challenge or opportunity?
Opportunity. South Korea is like an island; we are isolated, there are conflicts with neighbours and our mentality is divided over how to deal with North Korea.

How will unification transform Korea’s economy and society?
We will be able to move across the [Chinese and Russian] borders, accessing resources and labour. We may have to make North Korea a separate economic zone until it reaches a certain level of GDP.

Do you fear reunification or welcome it?
Both. My generation will suffer, but my children’s generation would benefit from a bigger nation and an enhanced economy.