Elbridge Colby, U.S. President Donald Trump's nominee for under secretary of defense for policy, prepares for his confirmation hearing before the Senate Armed Services Committee at the Dirksen Senate Office Building on Capitol Hill in Washington, D.C., Tuesday (local time). AFP-Yonhap

A nominee for U.S.' defense policymaking has suggested the possibility of accelerating the transfer of wartime operational control (OPCON) from the U.S. to South Korea, reviving questions regarding Seoul's readiness for the transition.

While the defense ministry is reiterating its official stance of "mutually agreed conditions" for the transfer, defense experts here stress the need for cautious yet proactive measures to enhance the country's strategic value to the U.S.

Elbridge Colby, U.S. President Donald Trump's pick for undersecretary of defense for policy, reaffirmed Trump's vision of strengthening capable allies like South Korea, in a written statement submitted to the Senate Armed Services Committee on Tuesday (local time).

When asked whether the OPCON transfer should be condition-based and what criteria should be met, he stressed the need for careful review.

"If confirmed, I would need to review this delicate issue carefully. On the whole, however, I believe that President Trump's vision of foreign policy involves empowering capable and willing allies like South Korea, and thus I support efforts to bolster South Korea's role in the alliance," Colby said.

He also highlighted that the two countries' alliance is "critical" to U.S. national security interests.

"The U.S.-ROK alliance is critical for U.S. interests, and a foundation stone of the U.S. geopolitical position in Asia. It is important that this critical alliance continue to be updated to reflect the broader geopolitical and military circumstances the United States and the ROK face," Colby stated.

The U.S. and South Korea initially agreed to transfer wartime OPCON by April 2012 but postponed it to 2015. The delay was based on three key conditions for the transfer: first, South Korea's acquisition of essential military capabilities to lead joint defense operations; second, the alliance's ability to effectively respond to North Korea's nuclear and missile threats; and third, a security environment on the Korean Peninsula and in the region that would be conducive to the transfer.

Colby has consistently maintained the view that the OPCON transfer timeline could be expedited. During a previous interview with a local media outlet last year, he expressed his support for a swift OPCON transition, stating that South Korea should take on "overwhelming" responsibility for its own defense.

In response to Colby's stance, South Korea's Ministry of National Defense reiterated its usual position on the OPCON transfer issue.

"This is not an official position of the U.S. government, so the ministry does not have an official stance on it either. However, the fundamental principle of a conditions-based OPCON transfer remains unchanged," a defense ministry spokesperson told The Korea Times, Wednesday.

"South Korea and the U.S. will uphold the existing principle that the transfer of OPCON will occur once mutually agreed conditions are met, while systematically and steadily advancing the transfer in a way that further strengthens the ROK-U.S. alliance and combined defense posture."

U.S. and South Korean Marine Corps reconnaissance troops conduct joint live-fire training with pistols and rifles in training areas near Dongducheon, Gyeonggi Province, on February 28. Courtesy of Republic of Korea Marine Corps

Defense experts here called for cautious approaches on the issue.

"The OPCON transfer is conditions-based, meaning it will only take place once the required conditions are met. Once the transfer occurs, U.S. forces in South Korea could leave at any time. This also means that the Combined Forces Command (CFC), which currently operates under U.S. leadership, would see its role significantly diminished after the transfer," Kim Yeoul-soo, research head of security strategies at Korea Institute for Military Affairs, told The Korea Times.

He noted that the transition must be approached with extreme caution, as the U.S.' level of involvement in a potential security crisis on the peninsula would be fundamentally altered.

Yang Uk, a defense expert and research fellow at Asan Institute for Policy Studies, emphasized that South Korea needs to prove its utility by strengthening regional defense partnerships in the Asia-Pacific region.

"Actually, this was a predictable development. From the start, the Trump administration — especially in its second term — has been focused on reducing the U.S. burden in alliance security. In particular, when it comes to conventional security, the administration believes that allies should take greater responsibility for their own defense," Yang said.

He explained that the OPCON issue is closely tied to the reduction of U.S. forces in South Korea and the increase in the South's defense cost-sharing contributions. Therefore, rather than simply meeting U.S. financial demands, South Korea must take the initiative to enhance its own strategic value as an ally.

"We need to increase our own defense budget in a way that ultimately strengthens the ROK-U.S. alliance. This should create the impression that we are actively supporting U.S. strategic interests, particularly in military preparedness against China and other regional threats."

Yang also emphasized the importance of not overlooking practical gains in nuclear security. He dismissed, as "nonsense," the idea — voiced by some within the country — that the U.S. administration would permit nuclear weapons development by South Korea. He argued that Seoul must focus on bringing essential nuclear assets to its side to ensure robust nuclear security.

"For instance, the two countries can separately allocate funds for nuclear defense cost-sharing. This includes the deployment of strategic assets on the peninsula, such as redeployment of U.S. tactical nuclear weapons, and South Korea can share costs for these key nuclear assets," he said. "This way, we'll be able to possess related nuclear assets, expanding our options."