A visit to South Korea by an Ohio class ballistic missile submarine is part of a reported broader new deterrence deal with the United States.
A U.S. Navy Ohio class nuclear ballistic missile submarine is reportedly set to make a visit to South Korea sometime in the near future. This will be the first time one of these submarines has made a port stop on the Korean Peninsula in at least four decades. This is part of broader plans to more visibly demonstrate America’s ability and willingness to use its nuclear capabilities to defend South Korea if need be in the face of growing concerns about threats from North Korea.
Multiple outlets reported on the expected submarine visit earlier today, citing unnamed U.S. government officials. This could be the first of many such visits by Ohio class ballistic missile submarines, or SSBNs. Each of the Navy’s 14 Ohio SSBNs can carry up to 20 Trident II submarine-launched ballistic missiles. The Trident II has a so-called multiple independently targetable reentry vehicle (MIRV) configuration and each one can carry up to 14 individual warheads. The Trident IIs are typically loaded with either W76-1 or W88 series warheads, which have estimated maximum yields of 100 kilotons and 475 kilotons, respectively.
A view of the USS Ohio showing its missile tubes open. DOD
However, it is largely understood that Ohio SSBNs conduct patrols with missiles that have fewer than 14 warheads apiece, as a byproduct of various arms control deals with Russia. In addition, Ohio SSBNs are now sailing with at least some of their Trident IIs fitted with at best a very small number – maybe even just one per missile – of low-yield W76-2 warheads.
In addition, the Washington Declaration will reportedly include a new U.S.-South Korean “nuclear consultative group.” This entity “will focus on ‘nuclear and strategic planning issues’ and give the South Korean side ‘new insights’ into how the U.S. plans for scenarios like a possible nuclear exchange,” Axios reported, citing an anonymous U.S. government official.
None of this is expected to involve the permanent redeployment of U.S. nuclear weapons in South Korea. American forces maintained a nuclear stockpile on the Peninsula for much of the Cold War, but the U.S. government decided to remove them in 1991.
It is worth remembering that one of the U.S. Navy’s four Ohio class guided missile submarines, or SSGNs, USS Michigan, did make a stop in Busan, South Korea, in 2017, amid a spike in tensions with the North. The Ohio SSGNs are not capable of employing nuclear weapons, with their launch tubes being repurposed to primarily fire Tomahawk cruise missiles. Those tubes can also be used to deploy other payloads, including uncrewed platforms. The four converted Ohios, overall, are extremely capable multi-purpose platforms that can carry out stand-off conventional strikes, act as motherships for special operations forces, serve as underwater intelligence fusion centers and command posts, and more, as you can read about in this past War Zone feature.
The Ohio class guided missile submarine USS Michigan in Busan, South Korea, in 2017. USN
The Ohio class ballistic missile submarine USS Maine arrives in Guam on April 18, 2023. USN
Shows of force around the Peninsula involving U.S. bombers, as well as other American and South Korean combat aircraft, have become routine in response to North Korean missile tests and other provocations, too. This all being said, the bombers in question have often been conventional-only B-1s, rather than nuclear-capable types. It’s also important to remember that these kinds of flights also occurred regularly for years prior to a period of detente between the United States and North Korea during President Donald Trump’s term in office.
The reported planned Ohio SSBN visit and other rotational deployments are part of a broader set of new agreements between the United States and South Korea, which will reportedly be collectively referred to as the Washington Declaration. This is set to be formally announced later today as part of South Korean President Yoon Suk Yeol’s state visit to Washington, D.C.
This also follows months now of Yoon and his government very openly lobbying for significantly increased South Korean participation in matters of deterrence on the Peninsula, particularly with regard to the possibility of retaliating against a North Korea nuclear strike.
In January, Yoon caused a stir by calling for more direct South Korean involvement in nuclear planning exercises with its American counterparts, something U.S. officials rebuffed at the time. The U.S. government’s response at the time seemed to be that it would continue to have active discussions about potential nuclear response options with its South Korean counterparts, but that it had no plans for any deeper coordination on their actual use. The expected establishment of a new U.S.-South Korean nuclear consultative group would seem to reflect continued discussions on this matter.
It is worth noting that, under current U.S.-South Korean agreements, should a full-scale war break out on the Peninsula again, the U.S. military would exercise operational control (OPCON) of all American and South Korean military units. Negotiations to transfer wartime OPCON of South Korean forces to the country’s independent military command structure have been underway for years now.
U.S. and South Korean personnel together at the Korea Air Operations Center at Osan Air Base, South Korea, during an exercise in 2010. USAF
Later in January, Yoon had gone one step further, implying that, depending on how the security situation on the Peninsula might evolve, his country could be compelled to develop its own nuclear weapons. This would, of course, be a massive shift in policy for South Korea, which is currently a signatory to the Nuclear Non-Proliferation Treaty (NPT). In light of this, the Washington Declaration is expected to also include a reaffirmation by the South Koreans of their obligations under the NPT, including to not pursue a nuclear weapons program.
A key element of the backdrop to all of this is North Korea’s steady demonstration in recent years of an ever-expanding arsenal of strategic and tactical weapon systems likely capable of delivering nuclear warheads, together with a growing stockpile of those weapons and the material needed to make more. Just in the past few years, North Korean forces have tested an array of differently sized ballistic missiles, including ones capable of being fired from submarines, railcars, and more protected static positions on land and underwater, as well as various mobile ground-based launchers. North Korea claims that one of these newer ballistic missiles is tipped with a hypersonic boost-glide vehicle, as well. On top of all that, just this month, the regime in Pyongyang conducted a test of the country’s first solid-fuel intercontinental ballistic missile (ICBM), an important leap in technology and capability.
Added to this are a slew of other munitions that North Korea says are nuclear-capable, or that there are indications it might be looking to fit with nuclear warheads onto. This includes ground-launched long-range cruise missiles, very large artillery rockets, and even a purported uncrewed underwater vehicle.
North Korean developments have already prompted something of a missile race on the Peninsula, with South Korea have demonstrated a number of its own new ballistic and cruise missiles in recent years. The South Korean weapons are all, at least for now, conventionally armed.
Altogether, today’s expected Washington Declaration would seem to be as much about trying to slow the overall arms race that is developing – and trying especially to put a stop to any talk about South Korean nuclear weapons – as it is about signaling American resolve to North Korea in support of its ally on the Peninsula.
The exact terms of the new arrangements do of course remain to be seen. If the reports so far are accurate, South Korea looks set to at least see the first visit by an Ohio class SSBN since the 1980s.
