South Korea should take back wartime operational control of its military forces from the US, according to Rep. Ahn Gyu-back, the chief special adviser for Democratic Party of Korea presidential frontrunner Rep. Lee Jae-myung.

Ahn, who is part of Lee's Democratic Party primary campaign, told The Korea Herald on Thursday it was his personal view that ultimately, South Korea should have full control of the country's forces. He said that the conditions-based approach to the transition of wartime OPCON, agreed upon by the two allies in the mid-2010s, could extend the delay infinitely.

"No country with the size of South Korea's economy doesn't have total control of its military. So it is only natural, I think, that we would assume the right to take charge of our own defense during war or peace," Ahn said during the interview.

Ahn, a five-term lawmaker who served each term on the National Assembly’s defense committee, is widely viewed as a likely contender for defense minister if Lee is elected. While Lee has yet to formally secure the Democratic Party’s nomination, speculation about his potential Cabinet picks is already mounting, fueled by his commanding lead in the polls over rivals across the political spectrum.

Ahn, referring to Ukraine as an example illustrating the importance of strengthening self-defense capabilities, said South Korea and the US could resume discussions for meaningful progress on the transfer. Not having full control of OPCON was turning the country's military into "mommy's boy," he added.

Asked whether taking full charge of the country's wartime OPCON, a divisive issue, would have public support, Ahn said that reclaiming sovereignty over defense matters did not mean a weakened alliance with the US. "This is about enhancing our ability to defend ourselves, which would be built on the foundation of the South Korea-US alliance," he said.

When Lee ran for president in 2022, one of his key defense pledges was to expedite the transfer of wartime OPCON. Also in 2022, after entering the Assembly as a lawmaker, Lee had argued that South Korea was capable of defending itself without relying on foreign troops. Lee, who is expected to clinch the Democratic Party’s presidential nomination Sunday, has yet to clarify his position this time on securing full operational control of the military — a longstanding objective of the liberal camp.

Ahn said Lee’s foreign and security policy would be rooted in a strong alliance with Washington, calling the South Korea-US partnership “the bedrock of the country’s national security.” During a televised debate Wednesday, Lee described his approach to North Korea as a “stick-and-carrot” strategy, which Ahn further characterized as a balance of “both cooperation and tension” in managing inter-Korean relations.

Ahn said that while withdrawing from the Nuclear Nonproliferation Treaty was “not an option” for South Korea, revising its atomic energy agreement with the US was considered necessary. The agreement currently prohibits activities such as uranium enrichment and spent fuel reprocessing.

"We can't have nukes, they're not worth having considering the costs of falling out of the NPT. That would mean we would be living in isolation on a lone island like Robinson Crusoe," Ahn said. "But we do have a lot of spent fuel from reactors that is accumulating. So we want to have the rights to peaceful use of nuclear technologies, such as the ability to reprocess."

Ahn said he believes support for rebuilding Ukraine, initiated by former President Yoon Suk Yeol's administration, should continue. "If it serves a peaceful purpose, and also serves South Korea's national interests, then we should go do it," he said.

Ahn added that for the sake of managing North Korea-related risks, South Korea needed to restore ties with Russia. "Whether it be China or Russia, we have to maintain a friendly relationship if it means we can pursue mutual interests," he said.