South Korean President Says Country Could Develop Nuclear Weapons

South Korean President Yoon Suk -yeol said the country could develop its own nuclear weapons or ask the U.S. to redeploy them on the Korean Peninsula if the threat from North Korea grows, in the first time a leader of the country has explicitly raised the prospect in decades.

The prospect of South Korea, a nonnuclear state, acquiring its own weapons threatens to destabilize nuclear disarmament efforts and inflame already high tensions with Pyongyang. The idea has long been rejected by the U.S. and previous administrations in Seoul, although polls have shown it is supported by a majority of the public in South Korea.

“If the issue becomes more serious, we could acquire our own nuclear weapons, such as deploying tactical nuclear weapons here in South Korea,” Mr. Yoon said after meeting South Korean defense officials on Wednesday. “But it is important to choose realistically possible options,” he added, saying that the U.S. and South Korea are discussing sharing information and jointly executing plans to deter North Korea’s nuclear threat.

South Korea’s presidential office released the remarks on Thursday, stressing that there had been no change in the country’s policy of abiding by the Nonproliferation Treaty. “In order to effectively deter North Korea’s threats, our government has been focusing on strengthening the U.S.-South Korea extended deterrence,” the presidential office said.

North Korean leader Kim Jong Un, shown on TV on Jan. 1, has launched a spree of weapons tests recently.

North Korean leader Kim Jong Un’s spree of weapons tests and growing nuclear threat have fueled a debate in South Korea over the deployment and development of nuclear weapons as a deterrent. Mr. Yoon has pushed for Washington to allow Seoul to be more involved in the management of nuclear weapons, including planning and joint exercises.

South Korea is protected under the U.S. nuclear umbrella, an agreement that says Washington will use its nuclear weapons to defend its ally. The U.S. withdrew its tactical nuclear weapons from South Korea in the early 1990s under a disarmament deal with the Soviet Union, and Washington has rejected calls to redeploy them.

Park Chung-hee, a dictator who ruled South Korea for nearly two decades before his 1979 assassination, had sought to develop nuclear weapons but dropped the plan due to opposition from the U.S., according to documents declassified in 2008. Mr. Yoon made the first significant comments from a South Korean leader on the possibility of nuclear armament since then, said Cheon Seong-whun, a former South Korean National Security Council official.

“Yoon’s remarks signal a paradigm shift in dealing with North Korea’s nuclear threat,” Mr. Cheon said.

South Korea’s opposition party condemned Mr. Yoon’s remarks, calling it “absolutely unrealistic” and inappropriate as tensions escalate on the Korean Peninsula. “If we pursue nuclear armament, how would we call on North Korea to give up its nuclear weapons?” opposition party leader Lee Jae-myung said on Thursday.

The U.S. remains committed to the denuclearization of the Korean Peninsula and South Korea has made clear they are not seeking nuclear weapons, White House National Security Council spokesman John Kirby said during a Thursday press briefing.

“What we are going to seek, jointly together with them, are improvements in extended deterrence capabilities,” Mr. Kirby said.

The only effective way to reduce nuclear threats on the Korean Peninsula is by curbing the proliferation of nuclear weapons, an NSC spokesman added.

Robert Einhorn, a senior fellow at the Brookings Institution and a former senior State Department official, said it wasn’t clear why Mr. Yoon would discuss a South Korean nuclear weapon now, but suggested it could be to placate domestic supporters, to prod Beijing to rein in Pyongyang, or to pressure the Biden administration for a bigger role in the development of the U.S.’s extended deterrent.

“Senior Yoon administration officials say they support reliance on a strengthened U.S. extended nuclear deterrent, not South Korea acquiring its own nuclear weapons, and they say they are working with American officials in an effort to strengthen it,” Mr. Einhorn said.

Support for developing nuclear weapons in South Korea has risen at times of heightened tension with North Korea. A poll by the Chicago Council of Global Affairs showed support stood at about 55% in 2018, when leaders from the two countries engaged in a series of summits. With negotiations stalled and North Korea on a missile-testing spree, support had risen to 70% last year.

Mr. Yoon’s remarks are aimed at signaling to North Korea that South Korea is willing to consider extreme measures if Pyongyang continues to threaten Seoul with its weapons program, analysts said. But it is unlikely that Washington will seriously consider more nuclear weapons on the Korean Peninsula as an option, they said.

When Mr. Yoon was elected in March he promised to take a tougher stance on North Korea. Last year, North Korea tested a record number of missiles and passed a law allowing pre-emptive nuclear strikes against the South.

Some South Korean lawmakers have called for the U.S. to permanently station nuclear-armed submarines or aircraft carriers near the Korean Peninsula. Others have suggested an arrangement similar to the North Atlantic Treaty Organization, in which South Koreans would be trained to deliver U.S. nuclear weapons in the event of a conflict. But Washington has rejected such calls.

Mr. Yoon has used increasingly heated rhetoric in recent weeks after Pyongyang flew five drones over South Korean territory last month. He has vowed punishment and retaliation against the North and said the U.S. nuclear umbrella isn’t sufficient to reassure the South Korean public in the face of an increasingly aggressive North Korea.

“The North Korean nuclear threat is not only a threat to South Korea or an issue of the U.S. merely protecting South Korea,” Mr. Yoon said on Wednesday. “It is now a common interest for South Korea, Japan and the U.S.”