U.S. pledges stronger nuclear deterrence, but is South Korea buying it?

Amid growing doubts in South Korea about the credibility of the U.S. nuclear umbrella, Washington and Seoul have agreed on new measures to counter North Korea’s rising nuclear threats, including regular deployments of American strategic assets to the region and closer consultation on U.S. nuclear planning against Pyongyang.

However, analysts question whether the steps outlined Wednesday by U.S. President Joe Biden and South Korean leader Yoon Suk-yeol will be enough to reassure a growing number of South Koreans who believe it is futile to try to persuade Pyongyang to abandon its nuclear arsenal and that it is better for Seoul to respond with its own nuclear weapons.

Outlined in the so-called Washington Declaration, the latest deterrence efforts call for the establishment of a nuclear consultative group (NCG) — modeled on nuclear consultations within NATO — to discuss nuclear and strategic planning, a move that provides Seoul with greater insight into, and presumably also a greater voice in, Washington’s plans for potential nuclear retaliation in the event of a North Korean attack.

The two sides also agreed to “immediate bilateral presidential consultations” in the event of such an attack and promised to respond “swiftly, overwhelmingly, and decisively,” said Yoon, who is on a five-day state visit to the U.S. to mark the 70th anniversary of the two countries’ alliance.

While the declaration states that Washington commits to “make every effort to consult” with Seoul and will “share information on nuclear and strategic weapon operations plans,” Biden stressed during a news conference that the U.S. president remains the sole authority over America’s nuclear arsenal.

The U.S. also agreed to regularly deploy its “strategic assets” — such as heavy bombers and aircraft carriers — in and around South Korea, while also announcing the first visit to the country by a U.S. nuclear-powered ballistic missile submarine since the early 1980s.

While Biden said Washington would not be stationing nuclear weapons on the Korean Peninsula, he warned North Korea that a nuclear attack against the United States or its allies and partners would result in “the end of whatever regime, were it to take such an action.”

The U.S. had stationed nuclear weapons in South Korea from 1958 but withdrew them in 1991 as part of an agreement with Moscow to end the foreign deployment of “tactical” nuclear weapons intended for use in the battlefield, such as nuclear artillery shells. However, conservative politicians in South Korea, including Yoon, had renewed calls for a redeployment in response to Pyongyang’s growing arsenal of nuclear-capable missiles.

Seoul won’t be building nukes

A key aspect of the Washington Declaration is that it reaffirms South Korea’s intention to stay within the Nuclear Non-Proliferation Treaty, an indirect vow by Seoul not to pursue an indigenous nuclear weapons capability.

“The Yoon administration is pledging to set aside the prospect that South Korea would develop and deploy an independent nuclear weapons capability in favor of a robust alliance-centered response,” said Scott Snyder, director of the U.S.-Korea Policy program at the New York-based Council on Foreign Relations.

The document also calls for a new bilateral tabletop exercise for responding to potential nuclear crises, while also strengthening existing mechanisms, including the Extended Deterrence Strategy and Consultation Group, to better prepare to defend against potential attacks and conduct simulations aimed at improving joint planning efforts.

Given its focus on strengthening “extended deterrence” — Washington’s commitment to deter enemies and defend its allies with military power, including nuclear weapons — experts view the Washington Declaration as an upgrade of bilateral defense ties.

“To me, the key here is much more enhanced, tighter consultations between allies, giving South Korea a greater role in planning and executing joint operations in addressing North Korea's increasing nuclear capabilities,” said Ji-Young Lee, a Korea expert and associate professor of International Relations at American University.

The significance of the declaration could be easy to downplay, given the nature of the bilateral relationship as defense allies, said Seong-hyon Lee, a senior fellow at the George H. W. Bush Foundation for U.S.-China Relations.

However, this marks a very important departure from policy under Yoon’s predecessor, President Moon Jae-in, who was widely seen as leaning closer to China, Lee said, calling the current president’s direction “180 degrees opposite.”

“More than ever, Yoon boldly displayed his country’s strategic clarity in siding with the United States, even shouldering harsh criticisms from China and Russia in his sympathetic remarks about Ukraine and Taiwan,” he said.

‘Not what many South Koreans wanted’

But while the declaration attempts to ease doubts about America's security commitment, experts say it may fall short of the concrete and credible steps the South Korean public has been seeking, particularly as it is unlikely to persuade Pyongyang to stop developing, testing or threatening to use nuclear weapons.

Lee called the declaration “a rhetorical assurance to dissuade South Korea from going nuclear and have the country continue to be bound by the Nuclear Non-Proliferation Treaty.”

Lee said the document fails to clearly mention any discussion on South Korea's possible development of nuclear weapons, its authority in nuclear reprocessing, or the redeployment of U.S. tactical nuclear weapons.

“This is not what many South Koreans wanted, so they will scratch their heads about what really was accomplished in this summit.”

Once a fringe position, support for the idea of South Korea developing its own nuclear weapons has spread rapidly in the country as doubts grow about Washington’s willingness to potentially sacrifice San Francisco for Seoul.

A spate of recent surveys show that a majority of South Koreans — including an astounding 71% in a wide-ranging poll taken in February last year — now believe the country should develop its own nuclear weapons, a move Yoon had earlier hinted Seoul could pursue.

Given the popular support for this alternative, Lee argues that Biden didn’t seem to fully appreciate how much is at stake for Yoon in South Korea.

“Without any substantive deliverables, Yoon is likely to face backlash at home and become an early lame-duck president, with his current support ratings dipping below 30%,” he said, adding that the leader is revitalizing the U.S.-South Korea alliance “at a huge political risk, domestically.”

“The South Korean public think Yoon made unilateral concessions to Japan, is too pro-American and made a huge concession in terms of South Korean semiconductor firms' investing in the United States, which many see as not making business common sense," he said.

Coming home empty-handed could indeed turn into a bigger-than-anticipated blow for Yoon, who is unpopular domestically and leads a minority in the National Assembly, especially with key legislative elections set for next April.

There is also the question about how China, North Korea’s sole ally and South Korea’s top trading partner, will respond to the Washington Declaration as more U.S strategic assets are brought closer to Chinese territory.

“Beijing won’t be happy, of course,” said Soo Kim, a former CIA analyst.

“During the summit, Yoon took another step towards Washington’s direction — much to Beijing’s consternation — so we should expect to see China respond and express its displeasure in kind,” added Kim, who is currently a policy practice area lead at LMI Consulting.

In fact, the Yoon administration seems to be moving Seoul away from its longtime position of strategic ambiguity toward Beijing.

The more Seoul steps away from China and closer to the U.S., the stronger the repercussions from Beijing will be, she said. At the same time, Kim suggested that Yoon’s government will have already taken Beijing’s likely reactions into consideration.

“Seoul is likely willing to confront these ‘costs’ for the greater benefit of a strengthened and invigorated U.S. alliance,” Kim added.