North Korea's Kim Jong Un could get his hands on some worrying military tech in exchange for throwing Russia a war lifeline

• Putin and Kim deepened their arms deal and defense partnership at a summit last week.
• North Korea could demand a range of capabilities in exchange for sending Russia weapons for its war.

North Korea fueled Russia's war in Ukraine when it needed it most with substantial shipments of ammunition, but North Korean leader Kim Jong Un isn't doing this out of the kindness of his heart.

What Moscow is offering Pyongyang in exchange is a mystery, but Korea experts say that some of the possibilities are deeply concerning.

Since September 2022, when the US first accused North Korea of providing ammunition to Russia to address shortages, there has been widespread speculation on how Kim is being repaid for this partnership.

When Putin and Kim met last fall for a summit that resulted in Russia getting the ammo it needed to replenish strained stockpiles at a critical moment, there were questions about what North Korea wants out of this. Those have resurfaced with Putin and Kim's historic meeting in Pyongyang last week, which saw the leaders reaffirm their strategic alignment and sign a major defense pact.

"I think this is the biggest threat emanating from the Korean Peninsula since the Korean War," Victor Cha, the senior vice president for Asia and the Korea chair at the Center for Strategic and International Studies, said.

He added that the "widespread ripple effects" will not only be felt by the Ukrainians on the battlefield but also throughout East Asia and by the US due to potential for North Korea to receive technologies to improve its nuclear program, missiles, submarines, and more.

Putin and Kim's deepening partnership comes as Russian forces are on the offensive in Ukraine, Russian glide-bomb attacks are causing significant destruction, and Ukraine is facing frustrating limitations on how it can use long-range fires to strike targets in Russian territory.

Support from North Korea — in the form of weapons and ammunition — helps Russia keep up the pressure. Suspected 152mm shells, 122mm rockets, and KN-23 ballistic missiles have fueled Russia's war effort.

Western and South Korean estimates on just how much ammo North Korea has sent vary, but the total is believed to be in the millions.

Putin's reliance puts Kim in a place where he can drive a hard bargain to get what he really wants. According to Cha, Kim's red carpet treatment of Putin last week, as well as the mutual defense pact they signed, indicates much more is likely at work here.

Nuclear-powered submarines

One of the biggest asks from Kim could be technology for nuclear-powered submarines, which North Korea is trying to build. Its submarines, including one launched last fall that looked heavily modified to carry more missiles, are conventionally powered, meaning they need to resurface to refuel. That makes them easy to spot and track.

North Korea currently maintains one of the world's largest fleets, with estimates ranging from 64 to 86 total subs. That includes mostly coastal, conventional, and mini-subs, but in January 2021, Kim announced plans to develop nuclear-powered subs, noting that design research had already been completed.

Nuclear-powered subs would give North Korea a major capability upgrade. The vessels would potentially be quieter, faster, more survivable in a conflict, and harder to locate, allowing North Korea to travel farther, potentially closer to the US or its allies, and launch missiles without detection.

It's unclear what specific aspects North Korea needs to build the vessels, but Kim could ask Putin for acoustic technologies to keep the subs quiet or help with any kinks in the nuclear propulsion process. Kim could also request financial assistance to build the subs, as some indicators suggest that North Korea may be unable to sufficiently fund the development of a fleet of nuclear-powered subs.

Kim may want to learn from Russia's experience with the vessels, which could help him avoid trials and errors in the building process. Russia is one of only a handful of countries that operate nuclear-powered subs, and it's fleet is quite capable.

Nuclear weapons

Another point of concern is that North Korea could get technology it wants for its nuclear weapons program and intercontinental ballistic missiles.

On Monday, US Deputy Secretary of State Kurt Campbell said discussions about what North Korea gets from Russia likely involve "nuclear or long-range missile-development plans, perhaps other things in energy and the like."

Over the past decade, North Korea has domestically produced a missile force, from short- and intermediate-range weapons to ICBMs and submarine-launched missiles. Most recently, it has shown off its development of what it says are hypersonic missiles.

The North is working to field a force of missiles that could overwhelm adversary defenses. Help with this process, as well as assistance developing countermeasures to defeat enemy missile defenses, could be a priority.

Satellite technology

Advanced satellite technologies would go hand-and-hand with North Korean ambitions. In September 2023, Putin actually promised Russia would help North Korea build satellites; Kim has repeatedly tried and often failed to launch satellites into space, with the most recent May 2024 test failing when the rocket exploded during the first stage of flight.

With a satellite network, North Korea could rapidly identify targets to strike with its missiles. That would bolster its capabilities for a preemptive strike against the US or its allies, giving them only a few minutes to respond before airfields, ports, and command and control facilities on and around the Korean Peninsula are struck.

Fighter jets, manufacturing, and more

There have also been suggestions that what North Korea might want from Russia includes fighter aircraft, which Cha said were not entirely concerning given the robust capabilities of South Korea's Air Force, as well as US airpower in the region.

North Korea's ammo production capabilities, too, could see improvements thanks to Russian involvement. Much of the country's stockpiles date back decades, and US and South Korean officials have raised doubts about the effectiveness of these weapons.

If Russia were to collaborate with North Korea on ammo production, or at the very least give it better capabilities, then North Korea could find itself with larger, more effective stockpiles for a potential conflict on the peninsula.

But how this plays out is not all about what North Korea wants. There's also the question of what Putin is willing to provide. Further support could depend on how the war in Ukraine goes or whether South Korea decides to directly provide lethal aid to Ukraine, as opposed to its current policy of sending it via the US.

During CSIS' The Impossible State panel discussion on Monday, Scott Snyder, the president and chief executive officer of the Korea Economic Institute of America, said that the dynamic between Moscow and Seoul could determine what Putin decides to give North Korea.

After South Korea threatened to provide lethal aid to Ukraine directly in light of last week's summit, Putin suggested the possibility of giving North Korea the military capabilities it wants. Cha said that "in a sense, he's got leverage that he didn't have before."