To Seoul, which finally understands its security runs through Kyiv

Introduction: a letter to an ally waking up

Madam, Sir, leaders of South Korea

As the NATO summit in Ankara, set for July 7 and 8, 2026, draws near, South Korea is intensifying its diplomatic and military consultations with its Asian and Western partners. This open letter is addressed to you, the leaders in Seoul, to welcome this strategic shift while underscoring the urgency of turning it into a lasting, concrete commitment.

According to information reported by WION and other diplomatic sources, the South Korean government is now seeking to carry more weight on international security matters tied to North Korea and China, an evolution that deserves to be recognized and encouraged by all Western partners.

Why this letter, why now

I write this letter at a pivotal moment: the axis between Pyongyang and Moscow has grown considerably stronger since the war in Ukraine began, with arms transfers and, according to several Western reports, the dispatch of North Korean troops to support the Russian war effort.

Seoul finally understands that its security can no longer be thought of in isolation from Europe: the war in Ukraine and the Pyongyang-Moscow axis have merged the world's security theaters into one. It is a belated clarity, but a welcome one.

The now-inseparable link between Ukraine and the Korean peninsula

North Korean soldiers on European soil

The reported presence of North Korean troops alongside Russian forces against Ukraine marks a major strategic precedent for Seoul: never before had Pyongyang directly committed soldiers to a conflict so far removed from the Korean peninsula.

This North Korean involvement in Europe demonstrates, in concrete terms, that the Asian and European security theaters are now interconnected, a reality South Korean leaders finally seem to be fully absorbing into their national strategic doctrine.

A troubling transfer of military know-how

Beyond the deployment of troops, Western experts worry about the potential transfer of modern military know-how between Russia and North Korea, particularly in ballistic missile technology, an exchange that could dangerously accelerate Pyongyang's offensive capabilities.

Every North Korean soldier sent to fight in Ukraine comes home, potentially, with modern combat experience and Russian technology in tow. That is a poisoned gift the West cannot afford to ignore.

Why South Korea has everything to gain by getting more involved

Collective security more necessary than ever

By strengthening its diplomatic and military ties with Western partners and the rest of Asia, South Korea is not merely making a gesture of solidarity toward Ukraine; it is investing directly in its own future security against a North Korea increasingly battle-hardened by its combat experience in Europe.

This logic of collective security, which now binds NATO together with Indo-Pacific partners such as Japan, Australia and South Korea, represents a major strategic evolution that Seoul has every interest in deepening further.

An industrial role already well underway

South Korea has already proven its worth as a supplier of military equipment to several European countries, notably through its export contracts for howitzers and tanks to Poland, illustrating the growing integration of its defense industry into the Western ecosystem.

Seoul is no longer a distant bystander to the war in Ukraine; through its weapons exports, it has quietly become a real actor in Western support. That role deserves to be claimed more openly.

The historical reluctance still lingering in Seoul

A traditional diplomatic caution toward Moscow

Despite this positive evolution, South Korea long hesitated to commit more firmly against Russia, seeking to preserve certain diplomatic and economic channels with Moscow, a caution rooted in complex regional geopolitical considerations.

This historical hesitation, documented by several Foreign Policy analyses, is partly explained by South Korea's fear of pushing Moscow even further into Pyongyang's arms, a strategic calculation that nonetheless loses relevance as that axis strengthens regardless.

A shift in posture that is finally accelerating

Recent developments, notably the confirmation of North Korean troops actively fighting in Ukraine, appear to have convinced part of the South Korean government that this excessive caution is no longer sustainable given the scale of the converging threat.

I welcome this shift in posture, belated as it is. A late awakening beats an eternal caution that ends up costing an entire region's collective security dearly.

What Seoul can learn from Ukrainian resilience

A lesson in resistance against an overpowering authoritarian neighbor

Ukraine, confronted with an authoritarian neighbor wielding vastly superior military resources, offers a striking example of national resilience from which South Korea could draw valuable lessons for its own permanent standoff with North Korea.

Ukraine's ability to rapidly mobilize its defense industry, innovate technologically under duress, and maintain national cohesion despite years of war constitutes a serious case study for South Korean military strategists.

Striking geopolitical parallels

Like Ukraine facing Russia, South Korea lives under the constant threat of a hostile, nuclear-armed neighbor, a situation that invites a natural solidarity between the two nations confronting structurally similar security challenges.

There is an obvious strategic kinship between Kyiv and Seoul that both capitals should fully embrace. Democracies threatened by authoritarian neighbors have every reason to stand shoulder to shoulder.

China, the unavoidable factor in every South Korean calculation

An economic neighbor and a strategic threat at once

China remains, for Seoul, both a major trading partner and, simultaneously, a source of growing strategic concern, notably because of its indirect support for North Korea and its regional ambitions in the South China Sea and beyond.

This duality considerably complicates South Korea's diplomatic room to maneuver, which must constantly weigh its immediate economic interests with Beijing against its long-term security imperatives against the China-Russia-North Korea axis.

A Western convergence Seoul must fully join

Facing this convergence of threats, South Korea has every interest in more firmly joining the Western front against China, regarded by Western capitals as one of the principal structural threats to the international order, alongside Russia, Iran and North Korea itself.

Seoul cannot keep playing the tightrope walker between Beijing and the West indefinitely. The moment is approaching when clear strategic choices will have to be made, and the sooner that clarity arrives, the better for regional security.

Japan's role in this new security architecture

A complex but indispensable historical partner

The historically tense relations between Seoul and Tokyo further complicate the construction of a fully integrated regional security architecture, despite the obvious convergence of their strategic interests in the face of the shared threats posed by China and North Korea.

Recent trilateral rapprochement efforts between the United States, Japan and South Korea represent a significant, if fragile, step toward closer security cooperation in the Indo-Pacific region.

Coordination still falling short of the challenge's scale

Despite this progress, military and diplomatic coordination between Seoul and Tokyo remains short of what the gravity of the regional situation would demand, a finding several Foreign Policy analysts attribute to persistent historical tensions between the two nations.

The painful history between South Korea and Japan is real and legitimate, but it can no longer serve as an excuse for insufficient security coordination in the face of such pressing shared threats.

What the West concretely expects from Seoul

Greater material support for Ukraine

Western partners hope South Korea will take a further step in direct material support for Ukraine, beyond the indirect exports already made to European countries, an evolution that would considerably strengthen the credibility of its stated commitment.

This increased support could take the form of direct deliveries of ammunition or defense equipment, an option Seoul has so far avoided out of diplomatic caution toward Moscow, but one that is becoming increasingly difficult to justify given recent developments.

A more assertive voice in international forums

Beyond material support, the West also expects Seoul to adopt a more assertive diplomatic voice in international forums, more firmly condemning Russian aggression and North Korean involvement in a conflict that directly threatens global collective security.

It is time for Seoul to stop weighing every diplomatic statement on the scale of excessive caution. The gravity of the current situation demands a clear voice, not timid diplomatic phrasing.

The internal obstacles Seoul will have to overcome

A public opinion divided over international engagement

South Korean public opinion remains divided over the extent of international engagement the country should undertake, with some segments of the population favoring an exclusive focus on the peninsula's immediate security challenges rather than distant theaters like Ukraine.

This internal division complicates the task facing Seoul's government, which must constantly justify to its population the concrete benefits of greater international engagement in conflicts perceived as geographically remote from citizens' daily concerns.

Economic considerations that also weigh in the balance

Significant economic ties between South Korea and certain trading partners indirectly connected to Russia or China add a further layer of complexity to any decision toward firmer engagement on the international geopolitical stage.

I understand these internal constraints, but history never remembers kindly the nations that let immediate economic interests dictate their silence in the face of manifest aggression.

The precedent Seoul could set for all of Asia

A model for other hesitant Asian democracies

If South Korea takes the step of firmer commitment to Ukraine and the Western front, it could set a significant precedent for other still-hesitant Asian democracies, including certain Southeast Asian countries, to adopt a clearer stance against authoritarian aggression.

This regional trailblazer role would considerably strengthen Seoul's diplomatic standing within the international community, while consolidating a more robust Indo-Pacific security architecture against combined Chinese and North Korean ambitions.

A historic responsibility to fully embrace

This moment represents, for South Korea, a historic opportunity to demonstrate its status as a responsible middle power, capable of shouldering international commitments worthy of its now globally recognized economic and technological power.

Seoul has the economic and technological means to be a major player in global security. All that is missing now is the clear political will to fully embrace this historic role within its reach.

The risks of prolonged inaction for Seoul itself

Heightened vulnerability against a strengthened authoritarian axis

If South Korea continues to delay a firmer commitment, it risks finding itself isolated against an increasingly coordinated and experienced China-Russia-North Korea axis, a scenario that would considerably weaken its future negotiating position.

This prolonged inaction could also erode the trust of its Western partners, who might legitimately begin to question Seoul's reliability as a strategic ally in the event of a major crisis directly involving the Korean peninsula.

The cost of wait-and-see in a rapidly polarizing world

In an international context growing more polarized between democracies and authoritarian regimes, prolonged hesitation is no longer a neutral option: it amounts, in effect, to a relative weakening of South Korea's strategic position against adversaries who, for their part, show no hesitation whatsoever in coordinating their efforts.

Wait-and-see is never a neutral position in geopolitics. Every day of delay in South Korean engagement directly benefits the very authoritarian axis Seoul claims to fear most.

What the Baltic precedent teaches South Korea

Nordic democracies that chose clarity over caution

The Baltic states, Poland and Finland have shown since 2022 that a clear stance against Russian aggression, far from inviting the feared reprisals, actually strengthens a democracy's deterrent credibility against authoritarian neighbors determined to test its limits.

South Korea could draw a direct lesson from this European experience: strategic ambiguity, far from offering protection, often ends up encouraging an adversary to probe more aggressively for the weaknesses of a partner deemed hesitant.

A direct parallel with South Korea's vulnerability to Pyongyang

Just as the Baltic states live under the direct threat of an unpredictable Russian neighbor, South Korea shares a border with a North Korean regime increasingly armed with the technology and combat experience gained in Ukraine, which makes this strategic comparison particularly relevant.

Ignoring this parallel would mean, for Seoul, underestimating how quickly a Moscow-Pyongyang military partnership can transform the balance of power on the Korean peninsula itself.

The Nordic democracies have proven that a firm position deters better than permanent caution. Seoul should take note before the lesson is imposed on it the hard way.

The economic weight Seoul could put on the scale

A defense industry among the world's most capable

South Korea has a defense industry capable of rapidly producing tanks, artillery and ammunition at scale, an industrial capacity several European countries still struggle to match despite their rearmament efforts since 2022.

This industrial power constitutes a considerable strategic lever that Seoul could mobilize more directly for the benefit of Ukraine and Western collective security, beyond the indirect deliveries already made through third countries.

Economic choices that also carry a political price

Committing more openly carries a real commercial risk for Seoul, particularly in its economic relations with China, South Korea's leading trading partner, which partly explains the historical caution observed so far in official statements.

But this short-term economic calculation must not eclipse the long-term security risk posed by an increasingly integrated authoritarian axis between Beijing, Moscow and Pyongyang.

I understand the commercial caution toward Beijing, but no export contract is worth an entire nation's long-term security against a consolidating authoritarian axis.

What Ukraine's recent history can inspire in Seoul

Resilience as the answer to a foretold aggression

Ukraine has shown since 2022 that a determined nation can resist far beyond even the most pessimistic initial forecasts, a lesson in resilience directly applicable to any democracy living under the constant threat of a militarily more powerful authoritarian neighbor.

For Seoul, this Ukrainian resilience concretely illustrates that preparation and strategic clarity are worth more than the fragile hope that an aggression will simply never occur.

A solidarity that could one day work in Seoul's favor

By standing with Ukraine today, South Korea is also indirectly building the kind of international solidarity it might itself need should a sudden escalation with North Korea occur.

This strategic reciprocity, often overlooked in immediate diplomatic calculations, deserves to be laid out clearly before South Korean public opinion as a substantive argument, not merely a symbolic gesture toward a distant country.

Solidarity with Kyiv is not a distant act of charity for Seoul; it is a direct investment in the solidarity it might one day depend on itself.

Conclusion: a letter of hope more than reproach

A sincere encouragement to continue this evolution

This letter is not meant as an indictment of Seoul, but a sincere encouragement to pursue and deepen the strategic evolution begun in recent months. South Korea has shown that it understands the interconnection of the world's security theaters, a clarity that deserves to be welcomed and reinforced.

A call to turn awareness into lasting action

The NATO summit in Ankara offers Seoul a valuable opportunity to turn this emerging awareness into concrete, lasting commitments, alongside Ukraine and all the Western democracies confronting the same converging authoritarian threats.

This letter ends on a simple conviction: Seoul has already begun to change, and that evolution deserves to be encouraged rather than reduced to the silence of easy reproach.

By Maxime Marquette, columnist

Columnist's transparency note

My acknowledged biases

I write this open letter as an observer convinced that the West, including its democratic Asian partners such as South Korea and Japan, must remain the strategic center of the free world against the converging threats posed by Russia, China, Iran and North Korea.

What I don't know

I do not know the precise timeline or exact scope of South Korea's future commitments toward Ukraine, as those decisions rest on internal deliberations in Seoul not yet fully made public. This analysis relies on verifiable journalistic and diplomatic sources, without unfounded speculation.

Sources

Primary sources

NATO — Overview: 2026 NATO Summit in Ankara, July 2026

WION — coverage of South Korean defense diplomacy, 2026

Foreign Policy — analyses of South Korea's strategic posture, 2026

Secondary sources

Anadolu Agency — Zelenskyy says Ukraine expects NATO Ankara summit will not become hollow exercise, 2026

Time Magazine — What to expect at the NATO summit, July 6, 2026

The Guardian International — coverage of Indo-Pacific alliances, 2026