In response to what is seen as increased Chinese aggression in Asia, Beijing’s growing military capabilities, and inadequate deterrence, an increasing number of U.S. policymakers and experts now call for Washington to create a grand, U.S.-led coalition of allies to counter and confront China.
Japan, South Korea, the Philippines, and Australia would supposedly form the allied core of such a coalition. And the coalition’s major security function would be to deter a Chinese attack on Taiwan. In this, Tokyo and Seoul would apparently play a particularly prominent role, given their proximity to Taiwan, their own significant military capabilities and housing of major U.S. military bases.
This notion is apparently endorsed by the Trump administration’s U.S. National Security Strategy that was released Friday. It calls for a collective coalition against Beijing, with its heavy emphasis on tightening U.S. and allied military coordination within the first island chain to counter China and “deny any attempt to seize Taiwan.”
The fundamental problem with this coalition concept, however, is that America’s Asian allies are far from united in support of it. Japan seems to be moving closer to the U.S. view of China in general and of Taiwan in particular, especially since its hawkish new prime minister, Sanae Takaichi, implied recently that Tokyo might intervene militarily to defend Taiwan if China attacked the island.
At the same time, Tokyo’s stance regarding the extent and manner of any Japanese military role beyond the direct defense of the home islands remains unclear. The Japanese public remains ambivalent at best about becoming involved in Taiwan’s defense. In partial contrast, Canberra and especially Manila seem more willing to become involved in a Taiwan conflict, but only indirectly, by defending their own territory against China or by providing non-combat support of various types. And the Australian public is deeply distrustful of the United States, particularly under Trump.
Compared to other regional allies, South Korea has been more reluctant to rally behind the idea of joining a U.S.-led anti-China coalition. Consecutive ROK administrations — conservative and liberal — have sought to position themselves carefully between Washington and Beijing. At the public level, support among South Koreans for the ROK-U.S. alliance remains strong, while sentiment toward China has become quite negative in recent years. Nonetheless, South Korean public opinion polls have also shown consistent support for maintaining a degree of diplomatic balance between Washington and Beijing rather than siding with the U.S. against China.
South Korean reservations and ambivalence about participating in a U.S.-led anti-China coalition could not have been made clearer when I recently traveled to Seoul as part of a Quincy Institute delegation to engage with the strategic community there, including current and former senior officials, major think tanks, university scholars, risk analysts, and journalists. Our South Korean interlocutors were clearly wary of China’s expanding power and influence, viewing it as a long-term regional challenge. But they also preferred to approach China cautiously and expressed strong reluctance to the idea of an allied confrontation with China or choosing between Washington and Beijing, especially in the military realm — including the prospect of fighting a war alongside the U.S. against China over Taiwan.
Our interlocutors offered a range of explanations for why South Korea needs to maintain some distance from the U.S. regional strategy to confront China. These included South Korea’s deep economic dependence on China, a lack of confidence (especially since Trump came to power) in Washington’s reliability as a security partner and its ability to manage relations with Beijing; tepid social feelings toward Taiwan among the Korean populace; and a fear that involvement in a Taiwan conflict could not only drag South Korea into an unwanted conflict with Beijing, but also undermine stability on the Korean Peninsula by drawing forces out of the country or encouraging North Korean provocations.
The South Korean public has virtually no desire to risk a war with China over Taiwan and wants very much for Washington to handle the issue in a restrained manner. And, according to our interlocutors, President Lee Jae-myung holds a pragmatic and balanced view toward relations with both Washington and Beijing, seeking to strengthen the ROK-U.S. alliance on the premise of mutual benefit while maintaining cooperative relations with China.
Seoul’s caution is primarily reflected in its stance toward what has been termed “strategic flexibility” regarding the use of the U.S. armed forces stationed in Korea (USFK) in contingencies outside the Korean Peninsula, especially involving Taiwan.
In 2006, under considerable U.S. pressure, Seoul agreed to allow USFK to be used outside the peninsula for regional or global contingencies. And in more recent years, joint U.S.-ROK defense statements have mentioned “peace and stability in the Taiwan Strait” as a shared concern, possibly indicating (at least from Washington’s perspective) that USFK could be used to address a Taiwan-related contingency. This view was reinforced by the 2023 Camp David joint statement among the U.S., ROK, and Japan, which stated that peace and stability in the Taiwan Strait were “indispensable,” thereby placing Taiwan on the trilateral security agenda and arguably moving Seoul closer toWashington’s view. And at least one senior USFK military officer has said privately that the U.S. could do “whatever it wishes” with U.S. forces on the peninsula.
Despite all this, Seoul has not gone beyond the above vague statements regarding “strategic flexibility” and possible “out-of-peninsula” contingencies. For example, this year, South Korean officials refused to clarify, despite urging by U.S. defense officials, how Seoul would respond to a future Taiwan conflict, and have continued to avoid giving the United States carte blanche use of USFK outside the peninsula, contrary to what some U.S. military officers might say.
In fact, the 2006 agreement stipulated that the USFK could not undertake any activities outside Korea that would harm South Korea’s security or were “against the will of the Korean people.” Seoul also insisted that any USFK deployments would require prior political consultation, if not explicit approval. As many of our interlocutors stated in describing Seoul’s concerns, USFK “beyond-peninsula” operations must not jeopardize Seoul’s deterrence capacity against North Korea or drag South Korea directly into a Taiwan conflict against the will of the Korean people. These stances have remained consistent since 2006 across several South Korean administrations, even though it is probably true that conservative governments have been and will likely be more susceptible to U.S. pressure than liberal governments.
For some of our interlocutors, the vagueness of the 2006 agreement implies that South Korea is not obligated to provide any direct political or military support for USFK missions outside the peninsula. Other interlocutors believe that some type of “rear-area” support for USFK might be possible and, for some, inevitable. And some Korean observers have speculated that long-standing talks about the adjustment of wartime Operational Control of military units on the Korean Peninsula might eventually involve a division of labor in which Seoul takes primary responsibility for peninsula security (e.g., by keeping Pyongyang at bay during a Taiwan conflict) while USFK enjoys a limited form of "strategic flexibility.” But none of this has been clarified between the two countries, and it is no doubt on the agenda of ongoing talks.
So, while the Taiwan issue has become a focus of USFK “strategic flexibility,” South Korean hesitancy and concern remain. Our interlocutors said debates in South Korea continue over: a) how much influence Seoul might exercise over the use of USFK in a Taiwan or other “out-of-peninsula” contingency; b) whether, in a conflict, the U.S. would expect South Korea to provide at least rear-area support in any USFK deployment beyond the Korean Peninsula; c) whether USFK air assets in a possible Taiwan conflict (likely the primary if not sole forces available) would be deployed only to bases in Japan, and whether this would reduce the chance of any Chinese attack on U.S. bases in Korea; and d) whether a Taiwan conflict would lead to Beijing encouraging North Korea to provoke South Korea, thus pinning down both South Korean and USFK to the peninsula. All these uncertainties are greatly complicating any effort to clarify South Korea’s stance toward a Taiwan conflict.
Taken together, these questions demonstrate that, at least from a security perspective, the desire of some American policymakers and strategists to form a grand U.S.-led, anti-China coalition of allies is a long way from being realized, particularly with respect to South Korea. This should, however, be regarded as a good thing. Washington needs to start thinking about how to work with its allies to reduce, if not eliminate, the possibility of a U.S.-China conflict over Taiwan (or any other contingency in Asia) through means other than by simply piling on ever greater levels of military deterrence aimed at Beijing. '
Both carefully defined deterrence efforts along with credible reassurances are needed. Some South Korean interlocutors even believe that a U.S. policy shift that rules out U.S. military intervention in a cross-Strait conflict — while maintaining strong support for Taiwan in all other respects — would benefit regional stability in East Asia. All in all, Washington would be wise to drop its promotion of an unrealistic pursuit of a grand anti-China coalition.
