The flow of troops, arms, and civilians between Russia and North Korea is moving both ways as casualties pile up and supplies run short amid freezing winter temperatures and tough Ukrainian resistance.

That hellish image emerges amid reports that fresh North Korean troops are pouring into the embattled Kursk Oblast region of Russia, hard by the eastern Ukraine border, after the initial wave of North Koreans suffered prohibitive casualties.

Wearing Russian uniforms and carrying Russian identification cards, the North Koreans are the tip of the spear of the Russian drive to turn back the Ukrainian forces that crossed the border in August, making up somewhat for the loss to Russia of the Crimean peninsula and much of the southeastern Donbas region more than 10 years ago.

“Russia has once again deployed North Korean soldiers alongside its troops,” Ukraine’s president, Volodymyr Zelensky, said in a social media post. “Hundreds of Russian and North Korean soldiers,” he claimed, “have been destroyed” in the latest fighting. “This is crucial because battles on Russian territory prevent further escalation against our cities and land.” 

A Seoul website that tracks North Korea, NK News, said North Korean troops had been redeployed to the Kursk region “after a brief withdrawal from the frontlines” — and “their tactics appear as deadly as before.” New to combat, unfamiliar with the flat terrain, and easy targets for Ukrainian drones, the North Koreans initially suffered about 1,000 killed and 3,000 wounded, a casualty rate of a third of the 12,000 troops that North Korea’s leader, Kim Jong-un, had sent there.

How much they learned, though, is open to question. NK News quoted the chief of Kyiv’s Center for Countering Disinformation, Andrii Kovalenko, as saying “the same assault groups are now advancing head-on and suffering losses” even though “they were previously withdrawn and not used in assault operations after sustaining casualties.”

Going the opposite direction, a Russian newspaper, Rossiyskaya Gazeta, reports “hundreds of Russian soldiers” wounded in Ukraine are being treated in North Korea. Russia’s ambassador to North Korea, Alexander Matsegora, described “the hospitality” accorded the Russians as “a reflection of North Koreans’ warm attitude toward Russians,” said the report. 

North Korea and Russia, he was quoted as saying, share “a common history filled with examples of close cooperation and mutual assistance.”

So generous were the North Koreans, the ambassador said, that they “refused Russia’s offer of financial compensation for the medical care, food, and other expenses related to the Russians’ stay in North Korea,” according to the Washington-based Institute for the Study of War. He neglected to mention that Mr. Kim had promised President Putin vast quantities of arms and thousands of troops. 

The influx of wounded Russians into North Korea, though, may have a dual purpose — “part of the military training programme for the North Korean soldiers and the exchange of combat experience,” Ukrainska Pravda said on its website.

“The Russian military command has reportedly been sending wounded personnel back into assault groups without treatment, demonstrating a general disregard for soldiers’ health in the Russian military and calling into question official Russian claims to be sending Russian soldiers abroad for treatment, particularly to North Korea.” the Institute for the Study of War said.

In fact, ISW said, “The arrival of combat experienced Russian soldiers, particularly if they include officers or non-commissioned officers, to North Korea may allow the Russian military to work with North Korean forces and disseminate lessons from the war in Ukraine while ostensibly recuperating.”

The traffic between Russia and North Korea also includes students on internships and professors on long-term deals to teach Korean in Russian universities. South Korea’s National Intelligence Service reports, moreover, that North Koreans “are increasingly entering Russia on student visas to take construction jobs,” ISW said. 

Civilians living in areas under Russian control may suffer the most. “The human costs of this war are enormous,” two professors, Peter Liberman at City University of New York and Andrew Kosenko at Queens College, write in Foreign Affairs. “Russian forces are ruling occupied Ukraine with an iron fist, engaging in a ruthless campaign of torture, kidnapping, violence, and arbitrary killing.”