Hours earlier than President Donald Trump introduced a return to U.S. nuclear testing “on an equal foundation,” he made one other shock announcement: He had given South Korea “approval to construct a Nuclear Powered Submarine.” Buying a conventionally armed, nuclear-powered submarine, or SSN, has been on South Korea’s protection want checklist for years—however even Seoul was caught off guard. This proposed functionality raises important questions that lack clear solutions.
Thus far, solely nuclear-armed states have developed and deployed nuclear-powered submarines. However South Korea wouldn’t be the primary nonnuclear state to pursue this technologically troublesome and politically delicate functionality. Australia and Brazil are within the midst of the lengthy technique of buying SSNs.
Hours earlier than President Donald Trump introduced a return to U.S. nuclear testing “on an equal foundation,” he made one other shock announcement: He had given South Korea “approval to construct a Nuclear Powered Submarine.” Buying a conventionally armed, nuclear-powered submarine, or SSN, has been on South Korea’s protection want checklist for years—however even Seoul was caught off guard. This proposed functionality raises important questions that lack clear solutions.
Thus far, solely nuclear-armed states have developed and deployed nuclear-powered submarines. However South Korea wouldn’t be the primary nonnuclear state to pursue this technologically troublesome and politically delicate functionality. Australia and Brazil are within the midst of the lengthy technique of buying SSNs.
The Australian and Brazilian SSN fashions are distinct in design, nuclear gasoline sort and sources of provide, and the depth of international partnerships concerned. Australia has partnered with the UK and United States by means of the AUKUS association. Early indications, together with a joint reality sheet launched after Trump’s go to to South Korea, counsel that Seoul would possibly observe the Australian mannequin, by which it may associate with the US and maybe one other nation to design and produce the boat and gasoline.
Most significantly, the US would offer the nuclear gasoline—enriched uranium—for the submarines, so South Korea wouldn’t want its personal enrichment functionality for gasoline manufacturing. This mannequin would, although, require a major set of amendments to present agreements and new preparations for Washington to share delicate army know-how with Seoul. This might be a major departure from the earlier U.S. place that the switch of SSNs and related know-how to Australia was a “one-off.”
If the 2 sides can not attain an appropriate association on the switch of U.S. gasoline, South Korea may as a substitute pursue the Brazilian mannequin. It’d obtain assist from the US in designing the nonnuclear elements of the submarine—akin to France’s help to Brazil—however would wish to develop a wholly indigenous nuclear reactor to energy the boat. It could additionally want to supply the nuclear gasoline to energy that reactor. South Korea doesn’t presently have its personal enrichment functionality, and its civil nuclear cooperation settlement with the US restricts cooperation on enrichment. The joint reality sheet signifies that this might change sooner or later, however a lot stays to be negotiated.
A intently associated situation is whether or not South Korea would gasoline its SSNs with low-enriched uranium (LEU) or extremely enriched uranium (HEU). Seoul reportedly sought U.S. provision of LEU gasoline prior to now, suggesting a naval reactor extra like Brazil’s LEU design. LEU can’t be used as readily in nuclear weapons as HEU and thus in and of itself raises fewer safety considerations. Nonetheless, HEU-fueled submarines don’t require refueling throughout their service lives and have some further efficiency advantages.
The USA makes use of HEU-fueled SSNs and, below the phased method to the AUKUS settlement, plans to ultimately switch HEU gasoline to Australia for its future SSN fleet. Whatever the stage of enrichment—and whether or not South Korea makes its personal gasoline or receives it from the US—Seoul might want to negotiate a particular safeguards association with the Worldwide Atomic Power Company (IAEA).
There are presumably different pathways South Korea may pursue past the Australia and Brazil fashions, even with U.S. help. Trump clearly indicated an expectation of U.S. involvement given his follow-on submit about constructing these submarines within the “Philadelphia Shipyards,” a reference to Hanwha Philly Shipyard, not too long ago acquired by the South Korean group. However that shipyard is not kitted out with the amenities and capabilities wanted to assemble nuclear-powered boats, and South Korean officers are insistent that the submarines might be in-built South Korea.
However why does Seoul even need a nuclear-powered submarine within the first place? SSNs have some operational benefits over what Trump described in his unique submit as “quaint, and much much less nimble” diesel-powered submarines: They are often quicker and stealthier and journey farther and keep submerged longer than their diesel-powered equivalents. However they’re additionally costly—financially, politically, and in any other case.
The pace and stealth of those submarines may assist South Korea put together for North Korea’s pursuit of its personal nuclear-powered submarine, which it seemingly plans to equip with nuclear weapons. South Korean SSNs may probably threaten this future leg of North Korea’s nuclear deterrent. If, nevertheless, North Korea depends on this future fleet as a safe second-strike functionality, holding in danger that functionality may considerably have an effect on Pyongyang’s strategic calculus.
The power of SSNs to journey longer and farther may probably contribute to burden-sharing efforts with the US. South Korean President Lee Jae-myung indicated that the submarines may enable South Korea to higher monitor North Korean and Chinese language vessels, assuaging the operational burden on U.S. forces. The query stays, although, whether or not this blue-water functionality is required to trace these property and whether or not the US would depend on it in a disaster or battle with China.
Past these operational attributes of SSNs, some in Seoul might have a really totally different curiosity in thoughts: utilizing the SSN program as justification for a uranium enrichment functionality that would contribute to the nation’s nuclear latency. There’s a long-standing debate in South Korea over whether or not to develop a nuclear weapons functionality to deal with the rising risk from North Korea. This debate has gained momentum in recent times, fueled by constant ranges of (probably underinformed) public assist for nuclear weapons, anxiousness over Washington’s prolonged deterrence dedication, and feedback from former President Yoon Suk-yeol that South Korea may develop nuclear weapons “fairly shortly.”
Whereas Yoon’s feedback had been walked again and the Lee administration has since reaffirmed South Korea’s dedication to not develop nuclear weapons, there stay vocal advocates for sustaining the nuclear possibility. An enrichment functionality would contribute considerably on this regard.
In the meantime, in a mannequin the place the US is central to each design and gasoline provide, these SSNs may function an vital standing image. South Korea would turn into solely the third nation—after the U.Okay. and Australia—with which the US would share this coveted and most delicate naval know-how.
Partnering with the US to construct an SSN program would see Seoul doubling down on its alliance with Washington—at a time when many in South Korea are involved about U.S. safety commitments amid fears that the Trump administration would possibly scale back the scale of U.S. Forces Korea.
Some commentators have interpreted this doubling down as a strategic transfer aimed toward positioning South Korea to straight contribute to and fortify U.S. trade. The South Korean need for an SSN functionality may additionally point out a willingness to broaden its involvement in regional safety past the Korean Peninsula. As a result of SSNs can journey farther for longer, a South Korean SSN may contribute to efforts to advertise higher regional stability. However none of this might occur in a vacuum, and severe questions stay about how others, specifically Beijing, would possibly reply to this expanded position.
There are authorized and political questions across the functionality, too. Growing a conventionally armed, nuclear-powered submarine wouldn’t prima facie violate South Korea’s nonproliferation obligations. Naval nuclear propulsion is a non-proscribed army use of nuclear materials based on South Korea’s safeguards agreements with the IAEA. However Seoul must negotiate a particular association to take away that materials from regular safeguards procedures, as required by its complete safeguards settlement, whereas it’s getting used as submarine gasoline.
Australia and Brazil are within the midst of such negotiations with the IAEA. This has been a yearslong course of throughout which each states have confronted quite a few challenges, together with worldwide pushback. South Korea may count on to face even higher pushback, and a few critics might even go as far as to accuse South Korea of pursuing SSNs as a canopy for a nuclear weapons program.
North Korea has already executed so, indicating that it’ll reply with “extra justified and sensible countermeasures.” China additionally raised nonproliferation considerations in a direct response to Trump’s announcement and cautioned Seoul to proceed “prudently.” Beijing’s diplomatic marketing campaign towards the AUKUS SSN program, or its political and financial response to the deployment of a U.S. missile protection system in South Korea, could be a mannequin for a way it could react to the event of South Korean SSNs.
Past these adversarial responses, Seoul may additionally count on combined reactions from its regional companions and allies, specifically Japan and Australia, which can query the influence of this South Korean functionality on allied deterrence. Japan, for instance, has already indicated that it might want its personal SSN functionality following Trump’s announcement.
Finally, additional readability and extra detailed evaluation are wanted to grasp and greatest put together for a future South Korean SSN functionality. The joint reality sheet offers few particulars, which may take many months and even years to work out. Its delay and studies of early divisions between Seoul and Washington (and inside Washington) on the matter portend many difficulties forward.
South Korea can even must assume by means of the implications of buying this functionality, particularly as related to the nonproliferation dimensions of naval nuclear propulsion by nonnuclear states. The worldwide neighborhood will need readability on how South Korea will proceed to ship on and show its dedication to its nonproliferation obligations. How can South Korea turn into a accountable steward of naval nuclear propulsion?
Regardless of the selections in Seoul, there are uneven waters forward.
