The Disastrous Downsides of South Korea Building Nuclear Weapons

38 North BY: SIEGFRIED S. HECKER, JANUARY 20, 2023

Is South Korea Willing to Lose Its World-leading Nuclear Power Program to Build the Bomb?

In a wide-ranging interview on January 11, South Korean President Yoon Suk-yeol warned Pyongyang that if North Korea’s nuclear threat continues to advance, South Korea would consider building nuclear weapons of its own or ask the United States to redeploy them on the Korean Peninsula. Although President Yoon walked back these comments at the World Economic Forum in Davos, they were published in the South Korean press and reinforced by some Republic of Korea (ROK) defense analysts. Cheon Seong-whun said, “President Yoon’s comment could turn out to be a watershed moment in the history of South Korea’s national security.”

A South Korean decision to build its own bomb could, indeed, be a watershed. Threatening Pyongyang does little besides give it a stronger justification to enhance its own nuclear arsenal. I believe that such a move would trigger a tsunami that would wipe out Seoul’s remarkable economic miracle and destroy the soft power it has established around the world……………………….

The National Burden of a Nuclear Arsenal

Whereas President Yoon’s comment, “…we can have our own nuclear weapons pretty quickly, given our scientific and technological capabilities” is true, it doesn’t come close to capturing the national redirection, expense, and immense burden that Seoul would have to shoulder to field not just one bomb, but a nuclear arsenal to counter Pyongyang’s.

It is true that with its advanced technological capabilities, South Korea could probably build the bomb quickly. But a few bombs don’t make a nuclear deterrent, particularly if Seoul will have to go it alone. And let’s be clear, if Seoul were to go down this path, Washington could, and likely would, withdraw its nuclear umbrella. Building a nuclear arsenal to counter Pyongyang’s would require a major national redirection of its economy and diplomacy that would negatively affect nearly all facets of South Korean life for decades.

For nearly fifty years, South Korea has pursued a civilian nuclear energy program. It wisely focused on the middle of the fuel cycle—that is, reactor fuel fabrication, reactor construction and operation, and electricity production. It has built neither enrichment nor reprocessing facilities. Consequently, South Korea has no inventory of bomb-grade plutonium or uranium currently stockpiled. To build nuclear weapons, it would have to repurpose some of its civilian reactors to produce the plutonium bomb fuel (combined with using its laboratory-scale pyroprocessing facilities to extract plutonium) or construct a centrifuge facility to make highly enriched uranium. Either path would take at least two years to produce enough bomb fuel for even a few bombs. In the longer term, an effective nuclear deterrent would require new, dedicated nuclear weapons facilities, requiring substantial time and financial commitments.

The next step in building a bomb is weaponization—that is, designing, building and testing the nuclear devices. South Korea could surely master all scientific and engineering challenges of building a bomb—as it has demonstrated so convincingly in mastering civilian nuclear power generation. Some of the purely military aspects could be accomplished in concert with its conventional military technical complex. But to prove the design and fabrication, there would need to be nuclear testing, but where? Neighboring countries—China and Japan—would certainly object strongly, and there would undoubtedly be strong domestic opposition to tests from every South Korean province.

The nuclear warheads will also have to be integrated into delivery vehicles—such as ballistic missiles, cruise missiles, submarine-launched missiles or bombers. South Korea has all the basic building blocks, but it would still have substantial work to do to integrate the nuclear warheads into the delivery systems. Moreover, these requirements will continue to evolve as North Korea upgrades its offensive and defensive capabilities. The assembly, disassembly and fielding of nuclear devices pose serious safety and security risks and would have to be learned without help or advice from current nuclear powers. Seoul will also have to develop a command-and-control structure that is more stringent than anything it has done so far for its conventional military.

Another consequence of building a nuclear arsenal is that it will compete for resources—financial, personnel, and technical—with the South’s conventional military…………………………………………………………………………

Seoul Would Deal a Serious Blow to the Nonproliferation Regime

South Korea would be the first democratic country to withdraw from the NPT, dealing a blow to decades of US leadership in preventing nuclear proliferation. As serious as the North Korean nuclear threat is, I believe Washington would have no choice but to condemn and counter the South’s decision to build the bomb. The nonproliferation regime is a complex fabric of treaties, agreements, assurances, practices, and international organizations. North Korea’s bomb and Iran’s pursuit of the bomb have already stressed the regime. The negative impacts of Russia’s invasion of Ukraine are playing out now. South Korea should not join these countries in undermining the regime……………………………………………………………

Shooting Itself in the Foot

South Korea’s decision to build the bomb will be widely condemned…………………………..

The irony is that an indigenous nuclear arsenal will make South Korea less secure. It is likely to draw an escalatory response from the North, and Seoul may then have to face that threat on its own. ………………………………. more https://www.38north.org/2023/01/the-disastrous-downsides-of-south-korea-building-nuclear-weapons/