[Global NK Commentary] Beyond the Assertion of 'Two Hostile States': Contemplating Korean Peninsula Unification

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Discussing the unification of the Korean Peninsula is not easy when North Korea defines inter-Korean relations as 'two hostile states.' It is contradictory for North Korea, which has long advocated for the abolition of the US's hostile policy toward it, to adopt a hostile policy toward South Korea. Furthermore, North Korea's constitutional amendment earlier this year deleted terms related to unification and the Korean nation while establishing territorial provisions that declared it is "contiguous with the Republic of Korea to the south." This legally enshrines its policy intention to define North and South Korea as separate states and block discussions on unification. However, in the sense that the division of the Korean Peninsula has created 'de facto two Koreas' for the past 80 years, not much has changed. This is why we must continue to contemplate unification even as North Korea abandons it. To continuously revitalize discussions on unification, a strategy that can move beyond the assertion of 'two hostile states' is needed. Unification, after all, is about two states becoming one. The unification of the Korean Peninsula will be a process where 'de facto two states' move beyond a 'hostile' relationship to peacefully form 'one state.' How should we design the unification of the Korean Peninsula when North Korea asserts 'two hostile states'? We need to learn lessons from historical cases of unification.

One of the significant characteristics of state unification since the 20th century is that it has rarely occurred through war. Vietnam is, of course, an exception. The representative cases of the 19th century, the unification of Italy and Germany, were achieved primarily through military force. In contrast, most unifications after World War II—again, excluding Vietnam—have been achieved through negotiation and, ostensibly, peaceful agreement.

The establishment of the United Republic of Tanzania in 1964 exemplifies this shift. Tanganyika and Zanzibar, having recently gained independence from Britain, decided to integrate through mutual agreement, and the country's name itself reflects this union. The German unification of 1990 also occurred peacefully, with East Germany being incorporated into West Germany through democratic and law-based institutional procedures. Yemen also achieved unification based on agreement in 1990, but it followed an exceptional path by subsequently descending into civil war.

The case of the Korean Peninsula shows a more complex trajectory. North Korea attempted unification by force through the Korean War in the 1950s but failed. Since then, both North and South Korea have, at least officially, avoided forced unification based on military power. South Korea has maintained the 'National Community Unification Formula' as its official unification policy for over 30 years, while North Korea has long advocated for a federal system of unification. However, Kim Jong-un appears to have effectively abandoned unification as an official goal recently.

Of course, the process of unification in the 20th century was not always smooth. In many cases, it was fraught with conflict and strife, and even if not full-scale war, it involved considerable turmoil. Nevertheless, the dominant path was negotiation rather than coercion. This trend appears to be attributable to the spread of democratic norms and the consolidation of the rule-based international order after World War II. Consequently, conquest or forced annexation have gradually lost their legitimacy as means of state formation.

Lessons from Unified States

In this context, the key lesson from historical experience is that unification has more often been a process of voluntary and negotiated integration rather than forced absorption. Existing typologies distinguish unification into models of absorption, agreement, trusteeship, and force. However, these categories often overlap and lack internal consistency. For instance, absorption can refer to voluntary incorporation, as in the case of Germany, or to forced annexation, as in the case of Vietnam. Therefore, a more analytically useful distinction is between voluntary and coercive paths, with war-based unification understood as a type of involuntary incorporation.

German unification clearly illustrates how these categories can become blurred. From a constitutional perspective, it was close to absorption, as East Germany was incorporated into West Germany. However, politically, it was based on agreement. Following the collapse of the Honecker regime, East German voters in the March 1990 elections supported rapid unification, and West Germany accepted the demands of East Germans, proceeding with unification through legal and institutional procedures. The convergence of preferences across both German societies formed the core basis of democratic legitimacy, a crucial factor distinguishing Germany from cases of coercive integration like Vietnam.

Tanzania shows another path, where integration was supported by social trust and close interaction built over a long period. Tanganyika and Zanzibar had maintained close relations for centuries, continuing cooperation through economic exchange and anti-colonial struggles. Thus, the decision to unify immediately after independence can be seen as the institutional consolidation of existing social bonds. Of course, there were procedural limitations in this process. Negotiations were centered around a limited group of political elites, and only Tanganyika underwent formal ratification. Nevertheless, this union has maintained its continuity based on deep social solidarity. Tanzania is considered a relatively successful case of avoiding the ethnic and religious conflicts experienced by many post-colonial states. Zanzibar continues to maintain a significant degree of autonomy within the union to this day.

Conversely, Yemen demonstrates how agreement-based unification can be unstable when domestic legitimacy is weak. North and South Yemen unified in May 1990 and ratified a new constitution through a referendum in 1991, but this agreement failed to establish a stable political order. Elite-centered negotiations and a weak institutional foundation led to the recurrence of conflict, ultimately resulting in the 1994 civil war and subsequent long-term instability. Meanwhile, Cyprus presents a case of failed unification based on negotiation following violent division. After inter-communal conflict and Turkish military intervention in 1974, the island remained divided, and the UN-led Annan Plan, put to a referendum in 2004, was rejected by Greek Cypriots, solidifying the division.

Synthesizing these cases, while it is difficult to make definitive statements, a general trend can be discerned. That is, unifications that secured strong domestic ratification and democratic legitimacy tend to exhibit greater stability, whereas unifications achieved through military force or based on elite-centered agreements with weak legitimacy are more likely to fail or face persistent conflict post-unification. This trend appears to be closely linked to the spread of democratic norms and changes in the international order throughout the 20th century.

Methods for Unifying the Korean Peninsula

This comparative analysis of historical cases holds significant implications for discussions on the unification of the Korean Peninsula. Where does South Korea stand in terms of the domestic and international conditions for unification? Is a unification path based on agreement and democratic legitimacy feasible? If an opportunity for unification arises, what conditions and phased procedures will North and South Korea need to manage the process in accordance with mutual agreement and democratic principles? More specifically, what do historical cases suggest about the political, legal, and social prerequisites for stable unification in South Korea?

Considering the current regional order surrounding the Korean Peninsula, unification through forced incorporation is highly unlikely. The theoretical possibility of unification through war cannot be entirely dismissed. However, given the dynamics of power balance and escalating conflict among surrounding major powers, it is practically almost impossible. In this context, the Constitution of the Republic of Korea and the National Community Unification Formula aim for a peaceful unification policy predicated on voluntary agreement, and North Korea's previously proposed federal system has also, at least formally, excluded unification by force and favored a negotiated path.

Article 4 of the Constitution of the Republic of Korea explicitly stipulates that unification must be pursued peacefully based on the fundamental order of liberal democracy. While the Constitution does not detail the contents of this fundamental order, its meaning can be inferred through Article 1. Paragraph 1 of Article 1 declares, "The Republic of Korea shall be a democratic republic," and Paragraph 2 stipulates, "The sovereignty of the Republic of Korea shall reside in the people, and all state authority shall emanate from the people." Taken together, these provisions imply that a lawful process of unification must be substantially based on national consensus. At the same time, these constitutional principles need to be more clearly concretized through specific legal frameworks and legislation.

Of course, the unification of the Korean Peninsula will unfold within its own unique temporal and geopolitical context. Mechanically applying historical cases to the Korean Peninsula is not only inappropriate but also undesirable. Nevertheless, the implications drawn from these cases remain significant. If South Korea is to draw lessons from past historical experiences, the core task is to determine how to enhance the possibility of voluntary unification based on negotiation and unification secured by democratic legitimacy. However, the Korean Peninsula currently lacks many of the prerequisites observed in successful unification cases. This deficiency explains why Germany was able to achieve unification at the end of the Cold War, while Korea, which was in a divided state during a similar period, could not.

Policy Implications and Future Tasks

First, from the perspective of unification based on agreement, South Korea must create conditions under which North Korea, South Korea, and surrounding major powers can voluntarily accept the unification process. North Korea's recent 'two hostile states' discourse can act as a significant obstacle, and the divergent interests among major regional powers can also limit the scope of agreement. As the German case shows, external actors are more likely to accept or actively support unification when the post-unification order aligns with their strategic interests. Therefore, South Korea's unification vision must be presented not as a destabilizing factor that alters the status quo, but as a result that provides a predictable security order and guarantees benefits—or at least tolerable costs—to the major stakeholders.

Second, from the perspective of democratic legitimacy, North and South Korea must prepare a path to unification that can secure reliable domestic approval processes. Sustained support from both South and North Korean populations is essential. However, public perception is becoming an increasingly significant challenge. Not only in North Korea but also in South Korea, indifference toward unification is growing. Young people, in particular, show skepticism about the necessity and expected benefits of unification. Concerns about the enormous financial burden, social turmoil, and post-unification economic instability—especially increased unemployment—are frequently raised. For South Korea's youth, already facing structural unemployment challenges, unification is often perceived as a distant and irrelevant issue. Meanwhile, the older generation tends to believe that the political feasibility of unification is diminishing, emphasizing the intransigence of the North Korean regime. Under these conditions, securing democratic legitimacy becomes very difficult. Regardless of how procedurally legitimate a process may be, it is difficult to achieve democratic legitimacy without sustained public support.

Third, in this regard, the debate surrounding unification costs is transforming unification from an ideal aspiration into a source of anxiety for some segments of society. Therefore, to restore public engagement, it is necessary to reframe unification not as a moral or symbolic goal, but as a concrete project of shared interests and opportunities. This includes presenting substantive arguments that the perpetuation of division itself incurs cumulative costs in economic, social, diplomatic, and security terms, which may ultimately exceed the costs of unification in the long run. This involves shifting the discussion from emotional appeals to an interest-based approach. In this context, South Korea must present a future-oriented vision that perceives unification as an opportunity to be realized, rather than a burden to be managed.

Fourth, compelling arguments for the benefits of unification must be constructed at various levels. Militarily, it can be emphasized that the gradual reduction of the constant defense burden due to division and the consolidation of peace and stability on the Korean Peninsula are possible. Economically, North Korea's development and expansion of infrastructure investment can be presented as new growth engines and sources of long-term productivity enhancement. Socially, it can be explained as an opportunity to heal the historical wounds caused by division and rebuild a political community where future generations can live with greater stability and solidarity. Diplomatically, by overcoming the state of isolation, akin to an island nation, caused by division and connecting overland with Eurasia, South Korea can strengthen its status as a middle power with an expanded population and economy. Politically, it can contribute to alleviating the polarization of domestic politics and social conflicts that have been exacerbated by persistent tensions on the Korean Peninsula, and create structural conditions for tension reduction not only between North and South but also within domestic politics. Ultimately, when this vision generates sustained domestic support, and at the same time, major external actors perceive the post-unification order as compatible with or potentially advantageous to their own interests, the window of opportunity for unification will finally expand.

The recent regression of democracy and the weakening of the rule-based international order are likely to alter the environment for South Korea's pursuit of unification. In this changing domestic and international political context, North Korea's adoption of a 'two hostile states' line and its explicit abandonment of unification as an objective can be interpreted as an attempt to expand its strategic space in response to evolving domestic and international circumstances. ■

■ Hwang Ji-hwan_Professor, University of Seoul.

■ Lee Sang-jun_EAI Fellow; Oh In-hwan_EAI Senior Fellow

Contact: 02 2277 1683 (ext. 211) | leesj@eai.or.kr