When South Korean President Lee Jae-myung lashed out at Ukrainian President Volodymyr Zelenskyy over a prisoner-of-war transfer in September, the reaction blindsided many and raised questions about why Seoul was escalating what seemed like a relatively minor diplomatic dispute.

Ukraine had captured the two North Korean soldiers fighting for Russia, and both reportedly wanted to go to South Korea. Kyiv eventually transferred them to Seoul, but when Zelenskyy mentioned the transfer during his speech at the United Nations, Lee publicly objected.

South Korea said the transfer was supposed to remain secret, while Ukraine said there was no nondisclosure agreement. Lee accused Kyiv of effectively “branding the head of state of the other country a liar” and warned that South Korea could take additional measures against Ukraine. Seoul did not let the matter drop. It recalled its ambassador from Kyiv.

No doubt Zelenskyy’s revelation was embarrassing to the South Koreans (the news provoked some criticism inside the country for a supposed appeasement of North Korea), but the reaction seemed overblown.

Perhaps something else was going on? And indeed it was. On October 6, The Guardian published an explosive investigation revealing that South Korea was shipping fuel to Russia. More than 176,000 tonnes, mostly diesel, had been loaded at South Korean ports onto seven tankers that made 14 voyages to Russia’s Far East in July and August. Three of those tankers were under British and European sanctions, and several declared destinations other than Russia before eventually sailing to Vladivostok. One sanctioned tanker never entered a South Korean port, instead receiving roughly 26,000 tonnes of fuel through a ship-to-ship transfer off Yeosu before heading to Russia.

The timing made the shipments more troubling. Ukraine had spent all year striking Russian refineries to cut the money and resources funding Russia’s war machine. Then in the summer, just as the impact was being felt inside Russia, South Korea stepped in to help Russia make up for some of the damage. In August alone, Russia imported 368,000 tonnes of oil products by sea, more than seven times what it imported the month before, and 112,000 tonnes, or 31%, came from South Korea.

The shipments do not appear to violate South Korean law, and the Guardian could not determine who owned or sold the fuel. But some of it was transported on sanctioned tankers and purchased by Russian companies under Western sanctions.

Was this what the South Korean president was trying to get ahead of? Did he know the investigation was about to be published?

That is difficult enough to understand on its own, but even more so when you look at what Russia has been doing for North Korea in exchange for Pyongyang helping Moscow wage its war against Ukraine. North Korea has supplied Russia with millions of artillery shells, ballistic missiles, and thousands of soldiers, while Russia has provided something that could eventually become far more dangerous for South Korea and the rest of the region: battlefield experience, training, and military technology.

Just last month, a new report from the Multilateral Sanctions Monitoring Team that tracks sanctions on Pyongyang found that Russia was bringing North Koreans into the country on student visas and putting them to work building military drones, including at the Alabuga drone factory. North Korean soldiers have also spent years fighting alongside Russian forces and have learned firsthand how a modern war is fought, from operating drones and dealing with electronic warfare to fighting against Western weapons. And they are taking that experience back home where it may one day be used against its southern neighbor.

This makes it even harder to understand what South Korea is thinking. In its latest defense report, Japan warned about the growing coordination between China, Russia, and North Korea, including Russian aid to strengthen the North Korean military and weapons development. And that is before considering what Russia is giving Pyongyang in return, including missile technology and other assistance that could help North Korea further develop its nuclear weapons and ballistic missile programs.

Russia is not some distant problem for South Korea. Moscow is helping North Korea become an even more dangerous threat, while Ukraine is fighting both Russian and North Korean forces. And if South Korea thinks appeasing Russia and, in turn, North Korea will make it safer, it is dead wrong.

On October 6, North Korea threatened South Korea with an “immediate and powerful counteraction” after a landmine blast seriously wounded two South Korean soldiers. Appeasement has never worked, and South Korea would be better off helping Ukraine defeat Russia and North Korea than picking a fight with Kyiv.

Olga Lautman is a non-resident senior fellow at the Center for European Policy Analysis (CEPA), the host of the Kremlin File podcast , and an analyst/researcher focusing on Russia, Ukraine, and Eastern Europe.

Europe’s Edge is CEPA’s online journal covering critical topics on the foreign policy docket across Europe and North America. All opinions expressed on Europe’s Edge are those of the author alone and may not represent those of the institutions they represent or the Center for European Policy Analysis. CEPA maintains a strict intellectual independence policy across all its projects and publications.

Illustration: An defense technology assembly diagram of a LUCAS drone. Credit: Sara Boyer/Center for European Policy Analysis.
Comprehensive Report

Unleashing Defense Innovation

By CEPA International Leadership Council

Building a future-capable force.

May 5, 2026
Learn More
Europe's Edge
CEPA’s online journal covering critical topics on the foreign policy docket across Europe and North America.
Read More