The geopolitically-charged issue of the 28,500-strong US Forces Korea's "strategic flexibility" appears to be reemerging as the Pentagon is working to craft a new defense strategy to prioritize deterring Chinese threats and increasing allies' "burden sharing."
The issue has gained renewed attention amid speculation that President Donald Trump's administration might strive to align USFK troops and other US military assets in the Indo-Pacific with his "America First" policy priorities to keep China in check and prevail in a potential contingency.
Greater strategic flexibility would mean the use of US troops in South Korea for a wider range of expeditionary operations, including roles for regional contingencies -- a move farther away from their traditional dedication to deterring North Korean threats.
Analysts said that from the United States' perspective, strategic flexibility might be a requirement for Washington to rebalance its military assets to optimize deterrence against China at a time when security challenges have become more convoluted due to Beijing's military buildup and its collaboration with North Korea and Russia.
For South Korea, the issue serves as a sobering reminder of geopolitical realities marked by a rancorous Sino-US rivalry, while it is raising anew a question over how to ensure that America's security commitment to the Asian ally remains robust and unequivocal.
"With the Sino-US relationship seen as edging closer toward confrontation beyond a phase of competition, the US may be much more explicitly looking to enhance strategic flexibility of USFK forces," Nam Chang-hee, professor of international relations at South Korea's Inha University, told Yonhap News Agency.
"Given the pressing challenge from China, the US may not want to dedicate USFK assets wholly to defending South Korea. It would want South Korea to take charge of the task to defend the Korean Peninsula, though that does not mean the US will abandon its nuclear umbrella protection of the Asian ally," he added.
Patrick Cronin, chair for Asia-Pacific security at the Washington-based Hudson Institute, described strategic flexibility as a "necessary planning requirement," pressed by increased regional and global security risks.
"The reality is that the president as commander-in-chief has always retained the ability to deploy US military forces as required to meet the national interest," he said. "Likewise, the South Korean president retains full control of ROK military troops except for those placed under CFC control."
ROK and CFC are short for South Korea's official name, Republic of Korea, and South Korea-US Combined Forces Command.
Cronin went on to say that the strategic flexibility questions are twofold -- how ready South Korea and the US need to be to grapple with simultaneous crises on and off the Korean Peninsula, and what the agreed-upon procedures are for redeploying forces on the peninsula for other contingencies.
Under Secretary of Defense Elbridge Colby is leading the charge to write the Pentagon's new National Defense Strategy under Defense Secretary Pete Hegseth's order to provide a final draft no later than Aug. 31.
During an interview with Yonhap News Agency in May last year, Colby underscored the need to adjust USFK's role to focus more on handling Chinese threats.
"US forces on the peninsula in my view should not be held hostage to dealing with the North Korean problem because that is not the primary issue for the US," he said. "The US should be focused on China and the defense of South Korea from China over time."
Strategic flexibility is not a novel concept at all.
Seoul and Washington agreed on the concept in early 2006 as South Korea's then Foreign Minister Ban Ki-Moon and then Secretary of State Condoleezza Rice issued a joint statement.
"The ROK, as an ally, fully understands the rationale for the transformation of the US global military strategy, and respects the necessity for strategic flexibility of the US forces in the ROK," the statement read.
"In the implementation of strategic flexibility, the US respects the ROK position that it shall not be involved in a regional conflict in Northeast Asia against the will of the Korean people," it added.
The bilateral understanding came as the US was pursuing a USFK troop realignment to ensure that they could deploy outside the peninsula to back an array of regional or global security missions -- a change triggered by the increasingly complex nature of threats, including those from non-state actors with no geographical definition.
But that realignment effort has encountered hurdles, such as Pyongyang's advancing nuclear and missile threats and Seoul's worries that the USFK's potential involvement in a conflict outside the peninsula could run the risk of South Korea's entanglement in it as a treaty ally.
The realignment efforts have seen US troops, including those once stationed in areas close to the inter-Korean border, relocate to Camp Humphreys, a sprawling US military installation in Pyeongtaek, a strategically vital rear area home to a fleet of US fighter jets and a major port.
That relocation has relieved once front-line US forces of highly sensitive border defense missions against North Korea, and given the troops more room to look beyond the peninsula and think more about deterrence against China, according to observers.
The US military has justified its intention to use USFK forces for off-peninsula missions based on the fact that the 1953 mutual defense treaty between Seoul and Washington does not identify a particular enemy. The treaty stipulates that collective defense coverage stretches to a broader Pacific region and territories under the two countries' administrative control.
During a forum last July, then USFK Commander Paul LaCamera pointed out that the alliance treaty does not specify an enemy, and that USFK is geared toward defending "all threats" to South Korea.
Most recently, a sign of strategic flexibility in practice emerged as USFK has recently deployed Patriot missile defense batteries to the Middle East on a temporary basis -- a dispatch that has brought the issue to the fore in both Seoul and Washington.
Bruce Bennett, a senior defense analyst at the RAND Corp., said that greater strategic flexibility would come at the cost of "somewhat" reducing US planning and training to handle North Korea and shift to handling a variety of other scenarios, especially Chinese aggression.
But he brushed aside concerns that strategic flexibility will reduce South Korea's overall security, as he asserted the need for South Korea to defend itself against the possibility of Chinese threats to its national interests.
"According to ROK public opinion polls, the vast majority of South Koreans do not trust China. That makes sense because China wants to dominate the region, which would include dominating South Korea -- a condition not in the interest of South Korea," he said.
"South Korea needs to be better prepared to handle this threat. So US planning and training to deal with China contributes directly to South Korean security and would assist South Korean military forces in also planning and training to handle Chinese aggression.
If the Trump administration seeks to increase USFK flexibility, Bennett said that it may want South Korea to raise its defense budget to better ensure Korea's own security and deal with other challenges.
"South Korea needs to increase its defense budget so that it can acquire more advanced weapons and have greater stockpiles of munitions and other supplies for future conflicts, as such preparations will strengthen deterrence of potential adversaries," Bennett said.
"South Korea also needs to deal with its military manpower challenges by creating a more professional component of its reserve force: making part of the reserve capable of offsetting the reduction in active duty personnel that has occurred over recent years and will continue in the future."
The resurfacing issue of USFK flexibility is expected to be an alliance topic that a new government in Seoul will face after the June 3 presidential election, analysts said.
"This will be a high-level defense equation that the next government might have to address," Nam of Inha University said. "That issue was something that has been glossed over, but it is increasingly becoming a real issue to be reckoned with."
Kim Tae-hyung, the president of the Korean Association of International Studies and a political science professor at Seoul's Soongsil University, raised the possibility that Trump could use the strategic flexibility topic to step up pressure on South Korea to jack up its share of the cost for stationing USFK. (Yonhap)
