US poll finds majority support for South Korea’s nuclear-powered submarines

South Korea’s proposed nuclear-powered submarine programme has the support of 58% of US adults surveyed by the Korea Economic Institute of America and YouGov, according to results KEI published on October 8. The same survey found that 71% opposed South Korea developing nuclear weapons. The findings show different public views of nuclear propulsion and nuclear arms as Seoul pursues its submarine project.

KEI and YouGov surveyed 1,207 US adults from August 21 to September 1, 2026. The results describe respondents’ views during that period; they do not establish a US government decision on the submarine project. Seoul Economic Daily reported a margin of error of plus or minus 3.6 percentage points for the survey.

How US adults viewed South Korea’s submarine project

Support for South Korea developing nuclear-powered submarines crossed party lines in the survey. KEI reported support from 56% of self-identified Democrats and 64% of Republicans, alongside the overall figure of 58%. Those figures concern a submarine powered by a nuclear reactor, rather than a finding that respondents favored South Korea acquiring nuclear weapons.

On the separate question of South Korean nuclear weapons, 71% of respondents opposed their development. That distinction is central to reading the results: a majority favored the proposed type of submarine while a larger majority rejected a South Korean nuclear arsenal. The survey records opinions about those two proposals, not whether either has been approved or put into operation.

What the poll found about the US-South Korea alliance

The alliance received broad support in the same survey. KEI said 64% of respondents believed it serves US national security interests, including 71% of Democrats and 73% of Republicans. The institute also reported that 68% held a favorable view of South Korea, a share it described as largely unchanged since it first asked that question in 2020.

Asked about the US military presence in South Korea, 48% favored keeping troop levels as they were and 8% favored increasing them, according to figures reported by Seoul Economic Daily. Together, those groups accounted for 56% of respondents. That question measured preferences about the existing troop presence; it did not ask whether the submarine project should proceed.

On a hypothetical North Korean invasion, 71% said they would favor using US troops to defend South Korea. This is another measure of stated public support for the alliance, rather than a prediction of a military response. Taken with the national security and troop-presence answers, it shows how respondents answered several distinct questions about US commitments to South Korea.

Views on North Korea and the limits of the survey

KEI reported that 87% considered it important for North Korea to give up its nuclear capabilities, compared with 85% in its 2020 survey. It also found that 68% held an unfavorable view of North Korea. Those results provide context for the survey’s Korean security questions, but they do not explain why any individual respondent supported or opposed South Korea’s submarine plan.

The publication gives a snapshot of opinion collected weeks before its October 8 release. The available summary does not provide the full questionnaire wording or detailed sampling and weighting methods, so the reported percentages should be read with that limitation in mind. The open question for the submarine project is what governments decide and implement; this poll establishes what its respondents said, not those subsequent outcomes.