In April 2023, the South Korean president flew to Washington.
The US gave Korea an offer.

Washington proposed that it would “periodically deploy American nuclear submarines to South Korea,” and in return, the United States demanded that South Korea remain a nuclear-free state and a staunch supporter of nuclear nonproliferation.

The Korean president accepted the US proposal.
It was called the Washington Declaration)

https://www.bbc.co.uk/news/world-us-canada-65404805

And in July, public polls showed that Koreans do not believe in defending the United States and 76% of respondents support the idea of arming their country with nuclear weapons.

https://www.koreatimes.co.kr/www/nation/2023/07/205_344519.html

And some murky movements and statements began from Korean Defense Minister Kim Yong-hyun. The US declaration is good, but the bomb is even worse.

https:/ /koreaherald.com/view.php?ud=202408160512

And then Batz and South Korean President Yoon Suk-yol accepted the resignation of Defense Minister Kim Yong-hyun, who suggested that he introduce martial law on the night of 3.

https://www.koreatimes.co.kr/www/nation/2024/12/113_387712.html

Maybe it's just a series of unrelated events, yeah.