U.S., South Korea Pledge Cooperation on Potential Use of Nuclear Arms
Seoul agrees not to develop its own arsenal while gaining more of a say in planning response to North Korea
WASHINGTON—The U.S. has agreed to give Seoul a greater voice in consultations on a potential American nuclear response to a North Korean attack in return for swearing off developing its own nuclear weapons, U.S. officials said.
The accord would grant South Korea’s leadership a long-sought place at the table on the use of U.S. nuclear forces to defend the country, though the U.S. would still retain control over targeting and the execution of nuclear operations. Seoul, in return, would restate its commitment not to develop its own nuclear arsenal.
The text of the agreement, which the two sides have called the Washington Declaration, will be released Wednesday when South Korean President Yoon Suk Yeol comes to the White House to meet with President Biden.
As a demonstration of America’s willingness to use its nuclear deterrent to protect South Korea, the declaration will say that a U.S. ballistic missile submarine will make a high-profile visit to the country.
The new accord comes against a background of anxieties in South Korea over the U.S.’s commitment to what foreign-policy experts call extended deterrence—Washington’s willingness to use nuclear weapons, if necessary, to defend South Korea despite the risk that North Korea could retaliate against U.S. territory.
Those South Korean concerns have been aggravated by significant advances in North Korea’s missile and nuclear arsenal, and the widespread view that diplomacy to denuclearize North Korea appears to be at an end.
Another factor has been the volatility of U.S. politics, which has prompted fears in Seoul that a future president would be less willing to defend South Korea against a North Korean military that has intercontinental-range missiles and a growing stockpile of nuclear arms.
In January, Mr. Yoon stirred concern in Washington by saying his country could develop its own nuclear weapons or ask the U.S. to redeploy on the Korean Peninsula if the threat from North Korea grows. It was the first time a leader of the country had explicitly raised the prospect in decades.
The U.S. deployed tactical nuclear weapons in South Korea in 1958, but removed them following the end of the Cold War with Moscow in 1991. The Biden administration isn’t planning to redeploy nuclear weapons on the Korean Peninsula.
Dissuading South Korea from producing nuclear arms has long been a bedrock principle for the U.S., which fears that such a move could encourage the proliferation of nuclear weapons in Japan and in other parts of the world, including the Middle East.
South Korea had a nuclear weapons development program decades ago but abandoned it under American pressure. In 1975, the country joined the Nuclear Nonproliferation Treaty, under which nations without nuclear weapons agree never to develop or acquire them.
The new accord outlines a series of steps intended to strengthen the two nations’ ability to deter an attack from North Korea, reassure the South Korean public and, as a result, dissuade Seoul from reconsidering the development of its own nuclear weapons.
It has its origins in a meeting Mr. Biden had with Mr. Yoon in Cambodia at a summit in November. The leaders discussed extended deterrence and instructed teams on each side to work on the declaration. In February, the two leaders agreed to make the declaration the centerpiece of Mr. Yoon’s April visit to Washington.
“The fundamental thrust of the Washington Declaration is to set forth a series of concrete ways in which the United States is reinforcing and enhancing its extended deterrence commitment to the Republic of Korea,” national security adviser Jake Sullivan said in an interview. “And the Republic of Korea is reaffirming its enduring commitment to its obligations under the Nuclear Nonproliferation Treaty.”
The new agreement will formally commit the U.S. to “make every effort to consult” with South Korea on the potential use of nuclear weapons. That will involve maintaining what the declaration calls a “robust communications infrastructure” to facilitate top-level consultations during a nuclear crisis.
The accord will establish a new Nuclear Consultative Group in which senior officials from the two countries would regularly meet to discuss how to reinforce deterrence and the cases in which nuclear weapons might be used.
Those deliberations, U.S. officials said, are expected to lead to new ways in which South Korean forces could train together in scenarios that could include a South Korean conventional military role in supporting U.S. nuclear forces in a conflict. This could include expanded exercises in which South Korean aircraft could escort U.S. bombers capable of carrying nuclear weapons. The North Atlantic Treaty Organization has had a similar program, in which fighters from nonnuclear nations escort warplanes that are designed to carry out nuclear strikes.
The Nuclear Consultative Group wouldn’t review specific targets but would focus on the North Korean nuclear threat and how the U.S. and South Korea might respond in a variety of situations.
“It will be the place to talk about what is the exact nature of the nuclear threat from North Korea and how is it changing,” Mr. Sullivan said. “It is a level up from any kind of target planning or specific operational planning. It is at the level of strategic scenario planning, threats, capabilities, responses.”
To reassure South Korea, the declaration calls for steps to spotlight the deployment in and around the Korean Peninsula of U.S. bombers and other strategic systems that are capable of carrying nuclear weapons. But it doesn’t provide for their continuous presence.
Robert Einhorn, a former senior State Department official who is now at the Brookings Institution think tank, said the agreement was an important step to strengthen deterrence and U.S. and South Korean ties.
“The U.S. and Republic of Korea have had a close, intimate relationship in discussions about conventional deterrence and defense,” he said. “But nuclear deterrence has essentially been off-limits to South Koreans. When South Koreans expressed an interest, they were basically told, ‘Don’t worry, we’ve got this.’ Now this stovepipe is being broken down.”
Other former officials say the declaration reassures South Korea but might be insufficient over the long run, given North Korea’s continued military buildup.
“It is a step in the right direction,” said Joel Wit, a former State Department official who is at the Stimson Center think tank. “But many South Korean government and military officials are not going to be satisfied until they have the finger on the button.”
Write to Michael R. Gordon at michael.gordon@wsj.com