How Trump defense pick points to focus shift from North Korea to China for US Forces Korea

U.S. president-elect Donald Trump's pick for senior defence official may signal his incoming administration's move to adjust the role of U.S. troops in South Korea to focus more on containing China, according to analysts.

On December 22, Elbridge Colby, who was the deputy assistant secretary of defence for strategy and force development during Trump's first term, was announced as the next under secretary of defence for policy, No 3 in the Pentagon responsible for the formation of national security and defence policy.

On his Truth Social account, Trump wrote that Colby would work closely with the secretary of defence nominee Pete Hegseth to "restore" Washington's military power and achieve a policy of "peace through strength".

Colby has been calling for U.S. military resources to be concentrated on a denial strategy against China's rise in the Indo-Pacific, instead of dispersing U.S. defence resources to other regions such as Europe, aligning with Trump's campaign pledge to end the wars in Ukraine and the Middle East.

A major contrast between traditional U.S. strategies in the Indo-Pacific region and Colby's overall policy agenda appears in the roles played by the U.S. Forces Korea (USFK) stationed in South Korea, a contingent that focuses on responding to North Korean threats.

Traditional defence officials in Trump's previous administration advocated for the USFK's role in responding to North Korean threats with a more hawkish stance against its nuclear and missile development.

However, Colby is sceptical that Pyongyang will give up its nuclear weapons and believes that U.S. troops in South Korea must instead be used to contain China's military threat, leaving Seoul to defend itself against North Korea.

South Korea hosts 28,500 U.S. troops in its territory — mostly army and air force personnel. Trump repeatedly said during his presidential campaign that South Korea must defend itself and should pay up to $10 billion for stationing U.S. troops in the country — nine times greater than the $1.14 billion expected to be paid in 2026.

In his 2021 book The Strategy of Denial: American Defence in an Age of Great Power Conflict, Colby argued that South Korea was likely to "grow increasingly challenging to defend from a determinedU.S.hinese assault" because of its proximity to China, but that including South Korea in the US defence perimeter against Beijing would be "worth the challenges."

"[South] Korea is important to the effective defence of Japan; if China were able to use South Korea as a base of operations, it would greatly complicate the defence of Japan," Colby wrote.

"Particularly given that the conventional military threat from North Korea has substantially receded in recent decades, if that from China grows, then South Korea and the United States can increasingly redirect their defence preparations toward defending against a potential assault by China."

Colby's repeated his position in an interview with the South Korean news agency Yonhap in May, when he said U.S. forces on the Korean peninsula "should not be held hostage to dealing with the North Korean problem" as it was not the primary issue for Washington and that the U.S. should be "focused on China and the defence of South Korea from China over time."

"South Korea is going to have to take primary, essentially overwhelming, responsibility for its own self-defence against North Korea because we don't have a military that can fight North Korea and then be ready to fight China," Colby said.

"The fundamental fact is that North Korea is not a primary threat to the U.S.. It would not be rational to lose multiple American cities to just deal with North Korea. That's a different calculation for South Korea ... We need to realistically evaluate an approach."

He also said "all options" should be on the table to ensure South Korea's security, including its nuclear armament in the face of a nuclear build-up in North Korea and China.

Patrick Cronin, chair for Asia-Pacific Security at Hudson Institute, said the second Trump administration expected allies to "shoulder more burdens to maintain a favourable balance of power," such as including South Korea in U.S.-led regional contingency plans.

"It is reasonable to expect Elbridge Colby, if confirmed as under secretary of defence, to elevate those efforts," Cronin said. "There are myriad ways, both direct and indirect, that South Korea could help contribute to security on and off the peninsula."

Kim Heung-kyu, director of the U.S.-China Policy Institute at Ajou University in Suwon, South Korea, said that with the nomination of Colby, the role of American troops in South Korea was expected to be "more focused on checking China than on the existing mission of suppressing North Korea."

"The importance of the USFK will be emphasised as it is the closest U.S. military located to China."

He said it was inevitable, however, that the U.S. military presence in South Korea would be reorganised and dispersed because of restructuring "according to the strategy vis-a-vis China".

He said Trump would try to "enhance his prestige and secure strategic flexibility by managing his relationship with North Korea" through negotiations, which could lead to discussions about South Korea's nuclear armament.

"China will naturally oppose South Korea's nuclear armament, but considering the stability of the Korean peninsula and its relationship with South Korea, it cannot unconditionally oppose South Korea's nuclear armament. Instead, [Beijing's] efforts should be made to establish an alternative military cooperation system that can stabilise this region or the Korean peninsula," Kim said.

Yoon Suk-joon, a senior fellow at the Korea Institute for Military Affairs in Seoul and a specialist in the Chinese military, said the role of the USFK was now "beyond the Korean peninsula", meaning that Washington sought to expand the scope of the alliance with Seoul to bring South Korea's military into its Indo-Pacific strategy.

Yoon said the U.S. Department of Defence and other institutions "think it would be more appropriate for an operational commander to go to the Indo-Pacific and North Pacific who can take care of North Korea, Russia and China together. That means that the role of the U.S. military commander in South Korea is now aimed not only at North Korea, but also at Russia and China."

Kang Jun-young, a professor of Chinese studies at Hankuk University of Foreign Studies in Seoul, said that in the South Korea-U.S.-Japan trilateral security cooperation, South Korea's priority was North Korea's nuclear weapons, while the U.S. and Japan's priority was to contain China. A problem may arise in "how to fill this gap."

"Perspectives from the Trump administration, especially from the defense sector, [are] that China and the U.S. could eventually go to war and - even if it is not a direct war between them - problems could arise in the Taiwan Strait or other places," said Kang. "So the role of U.S. forces in Korea should be adjusted in preparation for that."

Timothy Heath, a senior international defense researcher at U.S.-based think tank Rand Corporation, said that prioritising China as a responsibility "may make sense from Colby's perspective."

However, it raised the question of why Seoul should host U.S. troops if they were not defending South Korea from the North Korean threat, he added.

"It is unclear if U.S. forces would remain in Korea if USFK prioritises China over the DPRK," Heath said, referring to the Democratic People's Republic of Korea, or North Korea.

"If an agreement could be made where U.S. forces could participate in missions related to China as well as the DPRK, the main contribution in a Taiwan war would probably be the USFK's aviation forces and facilities."

Heath noted that "naval-based air forces could assist as well, though the long distance might limit how much they could participate."

Read the full story at SCMP.