South Korea considers nuclear arsenal amid rising regional tensions

South Korea is grappling with a transformative and potentially perilous decision: whether to pursue nuclear weapons.

South Korean dramas keep global audiences on the edge of their seats, and the country’s next potential thriller could be an explosive political drama: South Korea's potential move toward nuclear armament, Caliber.Az reports citing the local media.

What once seemed like science fiction is edging closer to reality. South Korea has considered going nuclear in the past, and this idea has gained significant traction recently. In early 2023, President Yoon Suk Yeol openly discussed the possibility of South Korea developing its own nuclear weapons. With North Korea’s nuclear arsenal expanding, public support for nuclear armament is high, with around 70 per cent of South Koreans now backing the idea. Kim Young-sik, a former district head on Yeonpyeong Island, emphasizes that without nuclear weapons, South Korea may struggle to defend itself against the North.

In response to concerns, the Biden administration has sought to reassure South Korea by reaffirming its commitment to “extended deterrence,” promising to protect its allies with its nuclear capabilities. A new consultative group has been established to integrate South Korea more closely into America's nuclear planning, and an American nuclear-armed submarine docked in South Korea last year for the first time since 1981. Despite this, President Yoon has recently downplayed the likelihood of South Korea pursuing its own nuclear arsenal.

However, if Donald Trump, who previously threatened to withdraw American troops from South Korea, were re-elected, the dynamics could shift. With North Korea's intercontinental missiles now posing a threat to American cities, doubts about America's reliability could intensify. Kim Young-sik reflects this sentiment: “If Trump becomes president, it’s even more reason for us to consider nuclear weapons. I worry that America won’t act if it risks its own interests.”

South Korea has compelling reasons to avoid nuclearization. North Korea, China, and Russia could respond with economic sanctions, aggression, or diplomatic pressure. Leaving the Nuclear Non-Proliferation Treaty (NPT) could damage South Korea’s global standing and lead to economic repercussions. While a third of 175 South Korean experts and officials surveyed by CSIS support an independent nuclear arsenal, many elites remain cautious.

Donald Trump might not be as disruptive as feared. The U.S.-South Korea alliance enjoys bipartisan support in Congress, which could block plans to move troops or complicate funding. The substantial U.S. military presence at Camp Humphreys, America’s largest overseas base, is difficult to replicate elsewhere. Trump may be satisfied if South Korea significantly increases its financial contribution to hosting American troops, possibly making this arrangement more palatable for South Korea.

But Trump could also undermine confidence in America's commitment, heighten fears of dragging South Korea into a broader conflict with China, or seek a deal with North Korea's Kim Jong Un. During previous negotiations, Trump halted large-scale military exercises with South Korea and had to be dissuaded from withdrawing troops. In a second term, with loyalists in key positions, Trump might have more freedom to act. Even a single tweet could erode trust in America's extended deterrence. In a recent CSIS survey, over half of South Korean experts opposed to nuclearization said their stance would change if an America First president were in office.

A historical parallel can be drawn from the early 1970s, when Richard Nixon, facing defeat in Vietnam, withdrew 20,000 of the 63,000 U.S. troops stationed in South Korea and urged Asian allies to assume greater responsibility for their security. This move sparked significant uncertainty about America's commitment. Though North Korea did not yet possess nuclear weapons, it had a conventional military advantage. South Korea’s then-president, Park Chung-hee, secretly pursued nuclear technology. When uncovered by American officials, pressure and security assurances were used to block it, leading South Korea to join the Nuclear Non-Proliferation Treaty (NPT) in 1975.

Today's dynamics could differ. Trump might be inclined to support or even encourage South Korea’s nuclear ambitions, viewing extended deterrence as a generous gesture rather than a strategic necessity. Recent visits by former officials close to Trump suggest a surprising openness to this idea. Mike Pompeo, Trump’s former Secretary of State, remarked that he saw no reason to oppose South Korea developing its own nuclear capabilities, considering North Korea's arsenal.

South Korea's potential nuclear path could resemble past proliferation episodes but with unique characteristics. According to Vipin Narang's "Seeking the Bomb," proliferators generally follow four strategies: hedging (keeping nuclear options open), sprinting (rapidly acquiring weapons), sheltered pursuit (developing weapons with a superpower's protection), and hiding (secret development). Currently, South Korea practices a form of hedging, reminiscent of its previous secretive efforts. However, given today’s interconnected world and vibrant democracy, any move towards nuclearization would be highly public and closely watched. Experts believe South Korea could potentially develop its first nuclear weapon within a year, either with or without American support.

Since the 1970s, South Korea has developed a world-class civil nuclear industry, renowned for its engineering expertise. With 26 reactors nationwide and South Korean firms building nuclear plants in the UAE and Czech Republic, the country has demonstrated its prowess. “The physics and science are already established. What you need now is excellent engineering,” notes Siegfried Hecker, former head of America’s Los Alamos nuclear laboratory. “And they excel in all aspects of nuclear engineering.”

However, South Korea lacks the essential materials for bomb-making: highly enriched uranium or plutonium from reprocessed nuclear fuel. Currently, the country’s nuclear industry does not reprocess spent fuel, and it imports enriched uranium for civilian reactors. South Korea would need to develop new facilities for large-scale reprocessing or enrichment. Despite this, it has stockpiles of spent fuel from civilian reactors that could potentially be used for weapons. A 2015 analysis by Charles Ferguson, then-president of the Federation of American Scientists, estimated South Korea has enough material for over 4,000 bombs.

South Korea might opt for a middle-ground approach similar to Japan’s, focusing on enrichment and reprocessing without pursuing full weaponization. This would reduce the time required to develop nuclear weapons in the future without crossing the proliferation threshold.

Yet, South Korea is well-positioned for full nuclear weaponization. “They are already a missile power,” says Ankit Panda of the Carnegie Endowment for International Peace. South Korea has advanced short and mid-range ballistic missiles, and is the only non-nuclear state to develop submarine-launched ballistic missiles. It would need to establish new command-and-control systems and a nuclear doctrine.

Testing nuclear devices presents a significant challenge. South Korea is densely populated and geographically smaller than New Mexico, making it difficult to find a suitable testing site. An atmospheric test would be highly provocative, and while computer simulations are advanced, they do not fully satisfy bomb designers.

Even after developing its first nuclear weapons, South Korea would face several challenges. North Korea, believed to have dozens of nuclear weapons, might accelerate its own arsenal in response. While South Korea wouldn’t need to match North Korea bomb for bomb, it would need a reliable retaliatory capability. The breakout period would be risky, with the possibility of accidental escalation and potential North Korean pre-emptive strikes.

Despite public support, domestic critics would likely oppose a nuclear program. Conservatives, who hold the presidency until at least 2027, might support nuclear armament, while some opposition Democratic Party members might favor it for strategic autonomy. However, others fear the irreversible nature of nuclearization. “The nuclear option is a one-way ticket—if we go forward, there’s no turning back,” warns Wi Sung-lac, a former ambassador and newly elected parliamentarian for the DP. Even if Trump supports South Korea’s nuclear ambitions, a future administration might reverse this stance.

Going nuclear would mark a radical shift for South Korea, changing its global identity from pop music and kimchi to nuclear power. International sanctions might be ineffective, with the U.S. potentially vetoing any punitive measures at the UN. South Korea could attempt to exit the Nuclear Non-Proliferation Treaty (NPT) under a clause allowing withdrawal in the face of "extraordinary events" threatening its "supreme interests," possibly garnering Western sympathy.

However, restrictions would likely follow. The Nuclear Suppliers Group (NSG), which regulates fissile materials, might urge its members to cut off cooperation with South Korea. The U.S. could seek an exemption at the NSG, akin to its approach with India, but without it, South Korea’s nuclear export industry would collapse, and its domestic reactors might shut down, reducing electricity production by about 30%. Testing a nuclear device would trigger American laws halting arms transfers and dual-use technology exports.

China might impose severe restrictions, potentially harsher than those seen after the deployment of an American missile-defense system in 2017. With about 20% of South Korea’s exports going to China and reliance on it for crucial components, such sanctions would significantly impact South Korea’s economy.

If South Korea proceeds with nuclear weapons, it could lead other nations dependent on American deterrence, like Japan, to reconsider their own nuclear options. “It’s not just about one nation going nuclear— it’s a domino effect,” says Richard Lawless, former Pentagon official for Asia.

Proponents argue that nuclear weapons are necessary to deter North Korea and may facilitate mutual disarmament through balance. Detractors warn that a nuclear South Korea could make the peninsula more dangerous, potentially sparking an arms race and increasing the risk of accidental conflict. As Mr. Lee points out, “What kind of peace is it if both have nukes? It could lead to an arms race and a dangerous situation where leaders on both sides might stumble into catastrophe.”