Existing Explanations of South Korea's Foreign Policy

There are several existing explanations for South Korea's strategies toward the US. First, geographic proximity of South Korea and China could play an influential role in influencing South Korea's foreign policy, with the expectation that South Korea would be more vulnerable to China based on its proximity. South Korea is closer geographically to China than most other US allies, with the exception of Japan. Even with similar proximity to China, Japan as a US ally acts differently than South Korea, so proximity could not be a major factor in understanding South Korea's foreign policy position toward the US and China.

Second, relative capabilities and power status could be a way to explain why South Korea has made specific policy choices in the context of the US–China rivalry. Power status can be measured by material indicators, such as the size of economy, population, and military expenditures (Holbraad Reference Holbraad1984; Wood Reference Wood1988). It can also be understood in behavioral or constructive ways, e.g., how a state demonstrates its foreign policy behaviors (Cooper, Higgott, and Nossal Reference Cooper, Higgott and Nossal1993; Henrikson Reference Henrikson and Cooper1997) or how a state socially constructs its identity (Hurrell Reference Hurrell2000; Neack Reference Neack2003; Shin Reference Shin2016). Generally speaking, major powers are states that have significant influence globally, and weaker states are ones with fewer influences regionally and globally. Yet, it is not easy to define what constitutes “weak,” “middle,” or “major” powers. Cox (Reference Cox1989), for instance, once considered Japan as a middle power, while people today would put Japan in the category of a major power. Still, power status matters in a state's foreign policy strategy because a state perceives its surrounding environment and then explores its policy options. States with relatively weaker capabilities are more vulnerable to threats and promises by major powers, while major powers are less vulnerable to other powerful states. Thus, states that have relatively weaker power could be less willing to balance against China given the US–China power game.

Many scholars use the framework of “middle power” to understand South Korea's foreign policy behaviors (Choi Reference Choi2009; Cooper and Mo Reference Cooper and Mo2013; Kim Reference Kim2014; Lee Reference Lee2009; Lee Reference Lee2012; Shin Reference Shin2016). Since 2008, following the Lee Myung-bak government, there has been a trend to describe South Korea's foreign policy in terms of its middle power status, or “Jung-gan-ja” or “Jung-gyun-guk,” the terms used by South Korean government and policy experts (Lee Reference Lee2012). With respect to its middle power diplomacy and foreign policy, South Korea has worked to strengthen its alliance with the US as a major power and committed to cooperation and multilateralism with other states, with an emphasis on the US-led rules-based order and peaceful global order (Choi Reference Choi2009, Karim Reference Karim2018).

Compared to South Korea, Japan is often considered a major power, and Australia as middle power or middle-major power, similar to South Korea (Cha Reference Cha2020). As a major power, Japan could have more leverage and ability to stand up against China, which supports Japan's assertive position against China. Despite its similar power status as middle or middle-major, Australia, another US ally, has been more assertive against China, leaning more closely toward the US. The Philippines, a US ally that is considered a weaker power and thus more vulnerable to a major power's threats, has been generally assertive against China as well. These diverging paths between South Korea, Australia, and the Philippines show that power status has limited explanatory power to understand different strategies among US allies given the US–China rivalry.

Alliance relations can play a role in explaining a state's foreign policy choices and strategies. There are many studies about the alliance structure in Asia and how these alliances affect the US–China rivalry (Beckley Reference Beckley2015; Cha Reference Cha2010; Harold, Grossman, Harding, Homung, Poling, and Smith Reference Harold, Grossman, Harding, Hornung, Poling, Smith and Smith2019; Hook and Son Reference Hook and Son2013; Jones, Smith and Khoo Reference Jones, Smith and Khoo2013; Lostumbo, McNerney, Peltz, Eaton, and Frelinger Reference Lostumbo, McNerney, Peltz, Eaton and Frelinger2013; Meijer Reference Meijer2020; Richey Reference Richey2019; Zhao Reference Zhao2011). The US has built multi-layered bilateral alliances with South Korea, Japan, the Philippines, and Australia, and to a lesser degree, Thailand. One important aspect of the US alliances in the region is that they are all asymmetric. Unlike the capability aggregation model of alliances (Walt Reference Walt1990), this so-called asymmetric alliance—relations between states with unequal power and capabilities (Lake Reference Lake2009)—is based on the security–autonomy trade-off where a stronger power provides enhanced security in return for a reduction in the lesser power's autonomy to some extent (Morrow Reference Morrow1991, Reference Morrow1993).

Many scholars have discussed the US–South Korea alliance in the context of asymmetric alliances and its implications for regional security (e.g. Bong Reference Bong2016; Chung Reference Chung2001; Ferrier Reference Ferrier2019; Heo and Roehrig Reference Heo and Roehrig2014; Kim Reference Kim2021; Lee, Prins, and Wiegand Reference Lee, Prins and Wiegand2021; Moon and Li Reference Moon and Li2010; Nam Reference Nam2010; Rozman and Lee Reference Rozman and Lee2006; Snyder Reference Snyder2012). Still, South Korea's unwillingness to clearly side with the US against China goes against the theoretical expectation of an asymmetric alliance in which a less powerful state is expected to mainly follow a stronger state's preferences as part of the security–autonomy trade-off. Asymmetric alliances provide a useful understanding about the relationship between the US and its allies in general, but they have limited explanatory power to explain South Korea's strategy in the US–China power competition.

Lastly, domestic politics are important in understanding states’ foreign policy decisions. Democratic governments are considered accountable to public opinion about international issues and disputes (Downs and Saunders Reference Downs and Saunders1996; James, Park, and Choi Reference James, Park and Choi2006; Wiegand Reference Wiegand2011; Wiegand and Choi Reference Wiegand and Choi2017). When it comes to the South Korean case, public opinion plays an important role in influencing South Korean foreign policy (Hwang, Cho, and Wiegand Reference Hwang, Cho and Wiegand2018). Public support for the South Korea–US alliance is steady and firm. The latest survey by the Asan Institute, conducted in March 2022, shows the US as South Korea's most favored country, with the average score of 6.85, while the favorability score of China, the second least favored country among the South Korean public in this survey, dropped from 3.25 in December 2020 to 2.71 in March 2022.Footnote ⁵ As indicated by the change in President of South Korea and President Yoon Suk-yeol's promised strategic shift away from former President Moon Jae-in, a shift in political party and leadership with different ideology and interests significantly influence its foreign policy.

Yet, South Korea's general strategies and positions toward China have remained fairly consistent among Korean presidents since 2011. Even with the Yoon administration's recent moves in siding more closely with the US, and a typical explanation that a more conservative government is expected to be more pro-US than the last government, the South Korean government maintains a strong relationship with China and has made consistent efforts to reassure China that South Korea is not hostile or antagonistic to China. Yoon's statements at the NATO summit in July 2022 were much tamer than expected: they “demonstrated that South Korea's foreign policy remains not just wary of China but actively constrained by Beijing. Both Yoon's rhetoric and policy agreements operated within the bounds of what is acceptable to China” (Chang Reference Chang2022). Thus, domestic public opinion and party affiliation are somewhat influential in foreign policy, but they also have a limited role in explaining South Korea's and other US allies’ strategies in the US–China rivalry.

US–China Rivalry, Territorial and Maritime Disputes, and South Korean Foreign Policy

We now turn to the discussion of our main theory of how the non-existence of active and ongoing territorial or maritime disputes between South Korea and China affects South Korea's foreign policy and strategic decisions—whether and to what extent South Korea overtly sides with the US while distancing from China. An overt siding with the US is considered as South Korea's involvement in bilateral and multilateral military cooperation with the US in targeting China in the broader Indo-Pacific region outside of the Korean Peninsula. When a US ally works with the US over the broader Indo-Pacific region and participates in either bilateral or multilateral military cooperation with the US in the region, it clearly signals that the country takes the side of the US against China, given the strategic power competition between the US and China. Due to its unique security situation with North Korea, it is inevitable and crucial for South Korea to closely work with the US via the ROK–US military alliance to deter North Korean threats in and around the Korean Peninsula. Yet, when it goes beyond the Korean Peninsula and stretches out to the broader Indo-Pacific region, such as the South China Sea, any direct involvement in US-led military actions to counter China's aggression would imply South Korea's willingness to counter China, as it is beyond what South Korea has previously pursued for the sake of its own national security and survival in its own soil.

We define territorial and maritime disputes as disputes between two states over their contested territory and/or maritime areas with direct government engagement diplomatically and/or militarily, following the Issue Correlates of War (ICOW) Project. In addition, we define “ongoing” territorial and maritime disputes as ones in which two governments are continuously contesting territory or maritime areas from the past to the present. In this sense, there are several active and ongoing territorial and maritime disputes between China and other states in the Indo-Pacific region, including Chinese maritime and territorial claims in the South China Sea against the Philippines, Vietnam, Malaysia, and Indonesia; China's territorial claim for Taiwan; China's maritime and territorial claims against Japan over the Senkaku Islands/Diaoyu Islands in the East China Sea; and territorial disputes between China and India over their unresolved land border (Dutton Reference Dutton2014; Emmers Reference Emmers2010; Fravel Reference Fravel2010, Reference Fravel, Pekkanen, Ravenhill and Foot2014; Kim Reference Kim2015; Koo Reference Koo2010; Liao, Hara, and Wiegand Reference Liao, Hara and Wiegand2015; Saha Reference Saha2015; Suganuma Reference Suganuma2000; Swaine and Fravel Reference Swaine and Taylor Fravel2011; Valencia Reference Valencia2007; Zhou Reference Zhou2015).

We argue that US allies with active and ongoing territorial and maritime disputes with China maintain hostile and tense bilateral relations with China in general and therefore, they are less hesitant to take a side with the US in balancing against China. An active and ongoing territorial or maritime dispute between a US ally and China has already provoked each state via their hostile territorial or maritime dispute. Having such tense relations and negative emotions over disputed territory and/or maritime areas, a US ally should be able to pursue more provocative foreign policy and position against China, in addition to their ongoing territorial or maritime dispute, including overtly siding with the US to balance China. Siding with the US in balancing China would lead to retaliation, but because the tensions are already high and the Chinese have already incurred costs to the US ally through the territorial or maritime dispute, retaliation for supporting the US against China would be minimal. Furthermore, such active and ongoing territorial and maritime disputes would be very likely to dominate overall discourse and interactions between the US ally and China, setting public emotions and political and social tones toward China, making it much easier for the US ally to be assertive toward China. Considering all, it would be very likely for the US ally that has ongoing territorial and maritime disputes with China to side more with the US in balancing and deterring China in the context of the US–China power competition.

The bilateral relationship between Japan and China is a good illustration of the above theoretical scenario. China has an active and ongoing territorial and maritime dispute against Japan in the East China Sea—the Senkaku/Diaoyu islands—with direct engagements with naval ships and government officials for several decades. Regardless of what position Japan has taken with respect to the US–China power competition, bilateral relations between Japan and China are already intense with heightened tensions and lingering hostility. If China becomes dissatisfied with Japan siding with the US against China, China may punish Japan. Yet, expected costs resulting from China's retaliations would be perceived as relatively minimal, as high costs have been already incurred from bilateral tensions based on their ongoing and active territorial and maritime dispute. As a result, Japan is more willing and likely to easily position themselves more closely to the US

South Korea, on the other hand, is expected to position itself more carefully between the US and China, because it has no active and ongoing territorial and maritime dispute with China. While there are unresolved maritime demarcation issues over the Exclusive Economic Zone (EEZ) and Air Defense Identification Zone (ADIZ) between South Korea and China over the Ieodo (Korean name; Suyan in Chinese and Socotra Rock internationally), these are latent disputes and not actively pursued by either state. As there are no ongoing or active territorial or maritime disputes between South Korea and China, there is no hostility that dominates overall discourse and interactions between South Korea and China like there is between Japan and China due to their territorial and maritime dispute. As there is no emotional backlash from territorial and maritime disputes, the South Korea–China relationship is relatively less antagonistic and fairly decent, compared to those with ongoing disputes.

Given decent relations with China, South Korea must consider not only how its strategic choices amid the US–China rivalry affect its alliance with the US, but also its current and future relationship with China. If South Korea clearly sides with the US and more actively balances against China, China can and will punish South Korea, at significant cost to South Korea. With no ongoing territorial and maritime disputes, China would likely retaliate with threats and punishment of South Korea via other important and critical issues. This kind of strategy is called issue linkage, in which a state deliberately links two or more distinct foreign policy issues together to use as bargaining leverage (Conconi and Perroni Reference Conconi and Perroni2002; Davis Reference Davis2004; Wiegand Reference Wiegand2011). We argue that, given no active, ongoing territorial and maritime disputes against China, South Korea is more likely to be cautious in its foreign policy strategies and positioning between the US and China, especially in order to prevent potential significant costs that it might pay over other critical issues.

In sum, we present our main hypothesis as follows:

Qualitative analysis of South Korea's strategies and position toward the US–China rivalry

South Korea has been very cautious in positioning itself between the US and China, especially as the strategic power competition between the US and China intensifies. South Korean governments have been very carefully maneuvering their foreign policy and strategic stance between the US and China, as observed in government-issued documents as well as many diplomatic incidences. There is no doubt that South Korea has continuously emphasized its commitment to the alliance with the US, not only to deter North Korea but also to address peace and stability in the region. The Moon Jae-in administration was the most recent progressive government of South Korea and put forth numerous efforts to engage with North Korea with as little friction as possible. Still, the Moon administration had expressed strong commitment to the US–South Korea alliance and peace and security in the Indo-Pacific, following US concerns and strategic focus on the region. At the US-ROK Leaders’ Joint Statement in May 2022, Moon, with Biden, emphasized “the importance of preserving peace and stability in the Taiwan Strait” (Work Reference Work2023, 139).

South Korea's commitment and fidelity toward the US–South Korea alliance has strengthened under the current South Korean President Yoon Suk-yeol and his administration. South Korea's 2022 Strategy for a Free, Peaceful, and Prosperous Indo-Pacific Region officially positioned its strategic focus beyond the Korean Peninsula and mentioned the Taiwan Strait along with the Korean Peninsula as important for security and prosperity of the Indo-Pacific, which is in line with what the US has underlined in its strategy in the Indo-Pacific. Similarly, Yoon also made bold comments on the Taiwan Strait that it is “not simply an issue between China and Taiwan but, like the issue of North Korea, it is a global issue” and tensions over Taiwan were “due to attempts to change the status quo by force.”Footnote ⁶

Still, it is important to note that even the Yoon administration has not weakened its relationship with China or openly confronted China. Despite Yoon's clear stance with the US, he has not explicitly named China as a threat or responsible in his comments, only implicitly signaling to whom he referred. None of the South Korean official documents under the Yoon administration overtly name China as a “threat” or characterize Chinese behaviors as “dangerous,” unlike what Japan has done or what the Japan–US Joint Leaders’ Statement did. For example, in August 2022, during South Korea Foreign Minister Park Jin's state visit to China in the midst of China's military exercises in Taiwan's territorial waters, Park made no official comments or mentions of China's aggressive actions. Rather, in what observers called a bid for reassurance, discussions with Chinese Foreign Minister Wang Yi covered bilateral cooperation and Chinese influence on North Korea, with Park citing “mutual trust” and “mutual beneficial cooperation,” which was interpreted as South Korea's continued intentional strategic ambiguity toward the US–China rivalry (Chang Reference Chang2022).

To further examine more in detail how South Korea has positioned itself between the US and China so far, we examined South Korea's Defense White Papers from 2014 to 2022,Footnote ⁷ as well as the 2022 Indo-Pacific Strategy.Footnote ⁸ Interestingly, South Korea has continuously referred to China as its “key partner” and underlined its “strategic cooperative partnership” with China in all of the government documents, showing its consistent efforts to maintain a decent relationship with China. South Korea's 2022 Indo-Pacific Strategy called China a “key partner for achieving prosperity and peace in the Indo-Pacific region,” which was also noted in the 2022 Defense White Paper. Regardless of whether progressive or conservative administrations were in office, as shown its official defense documents, South Korea has made consistent efforts to manage its relations with China in a good, decent manner and tone.

We also look at whether and how South Korea's official documents mentioned the South China Sea disputes and Taiwan since these are major points of contention between the US and China. This examination helps us gauge the degree to which South Korea is aligned with the US against China in its foreign policy and strategic position in these regional disputes. The 2022 Indo-Pacific Strategy and the 2022, 2020, 2016, and 2014 Defense White Papers mentioned the South China Sea, in terms of peace and stability in the region, freedom of navigation and overflight in the South China Sea, one of the important sea lanes, and even Chinese military activities in the region. Yet, what we found is that those comments about the South China Sea have been relatively neutral, as none of them seem to directly blame China as a direct threat or problem. Compared to the way Japan called out China as a concern and challenge in the South China Sea, South Korea has carefully managed such issues related to the South China Sea in its official defense document in a way that it has not aggressively provoked or directly antagonized China.

Peace and stability in the Taiwan Strait were mentioned in the 2022 Indo-Pacific Strategy and 2022 Defense White Paper, and US–Taiwan cooperation was mentioned in the 2022 Defense White Paper. It is very notable that both the progressive Moon administration and the conservative Yoon administration mentioned Taiwan in terms of peace and stability in the region, though none of such documents directly noted China as the problem. Similar to the South China Sea disputes, Taiwan was mentioned in a relatively neutral manner, in which South Korea has not directly called China a threat or a concern. In other words, even though South Korea mentioned Taiwan in accordance with the US, it has carefully treated such disputes in a way not to directly provoke China so that it would not get in the way of managing South Korea–China relations.

Most importantly, as there are no territorial and maritime disputes active and ongoing between South Korea and China, the overall tone of South Korea governments toward China has been relatively much less provocative, seemingly avoiding any direct confrontation with China. What are sometimes considered as potential territorial and maritime issues between South Korea and China are fishery and maritime demarcation in the Yellow Sea and the Air Defense Identification Zones (ADIZs) in the East China Sea where ADIZs of South Korea, Japan, and China are all overlapped in some degree. The 2016 and 2014 Defense White Papers had special appendix sections to discuss the Korea Air Defense Identification Zone (KADIZ) with respect to the ADIZs in the East China Sea and China. The 2016 Defense White Paper had a special appendix section to discuss Chinese illegal fishing in the Hangang River Estuary. Yet there was no direct condemnation of China as being a grave security concern or challenge in the documents, as Japan does with China over its disputes in the East China Sea. In fact, after 2016, there have been no more special appendix or section to discuss these issues. There have been brief comments about the KADIZ in the recent white paper, but none of the comments treated China as a security concern or challenge to South Korea.

Interviews with experts about South Korea's strategies over the US–China strategic competition

To test our hypothesis, we also conducted interviews with scholars, foreign policy experts, and retired military personnel from the US and South Korea to examine South Korea's strategies over the US–China power competition. The interviews were conducted from August 2021 to November 2022. Due to the pandemic and geographic limitations, most of the interviews were conducted virtually, while a few were conducted in-person.Footnote ⁹

Our interviews with experts support our argument of South Korea being very careful in positioning itself amid the intensifying power competition between the US and China because they are more vulnerable than other US allies that have tense relations with China. As noted by one of the interviewees, “South Korea's most difficult situation in the future is going to be navigating between the US and China,”Footnote ¹⁰ as South Korea should continue in its fidelity to the US–South Korea military alliance while also maintaining a strategically good relationship with China. Another expert directly pointed out South Korea's difficult position and the resulting need for careful and strategic maneuvering between the US and China:

As we argued in our theory, many of our interviewees noted that South Korea would experience significant costs if it were to side with the US and therefore provoke China. There was strong consensus among experts that South Korea would suffer very negative consequences if it took actions that were considered by China as balancing against China. One expert clearly pointed it out:

Similar concerns about China's costly retaliation over South Korea being closer to the US given the US–China power competition, as noted:

The interviewees support our argument that China would be likely to use an issue linkage strategy as a way to punish South Korea for siding with the US, leading to significant costs in other bilateral issues since there is no ongoing territorial or maritime dispute in which to focus. Almost all interviewees, in this sense, agreed that China would likely use economic ties, trade, and sensitive political issues, in particular North Korea, as effective issue linkage weapons toward South Korea to bring about significant costs to pay. One interviewee noted:

Regarding economic ties, interviewees mentioned how “China is a really huge market” for South Korea; that “economic consequences” were expected if South Korea took bold moves against China; and thus that “trade kinds of issues” are critical to South Korea with respect to the South Korea's position in the US–China rivalry.Footnote ¹⁵ Of China's issue linkage strategy and potentially costly retaliation against South Korea one interviewee said that “if [the] South Korean government takes side with the US in the case of Taiwan contingencies, what's next? I mean, that would be really serious problems not only in the military terms, but also in economic consequences.”Footnote ¹⁶

China's aggressive resolve against the deployment of the Terminal High Altitude Area Defense (THAAD) by the US in South Korea in 2016 is a representative example of significant economic costs that South Korea paid for antagonizing China in the context of the US–China rivalry. Although the deployment of the THAAD system was mainly to deter North Korea, China perceived it as a means of containing China and thus threatening behavior by South Korea against China. China responded to this perceived provocation with economic sanctions and suspended tourism, which cost South Korea nearly $7.5 billion in economic losses.Footnote ¹⁷ Echoing threats from 2016, immediately after the South Korean diplomatic visit to China in August 2022, China harshly responded to the potential deployment of further THAAD missiles in South Korea.

Almost all interviewees agreed that North Korea is a key issue for South Korea to consider with respect to its strategies toward the US balancing against China. One interviewee emphasized that “to us [South Korea], the biggest challenge is to resolve North Korean issues.”Footnote ¹⁸ Another expert echoes this point: “the North Korea issue is at the top of that list in terms of issues. You know, it's not something that is relevant to other countries in the region, but for Korea, that of course is the key or primary issue.”Footnote ¹⁹ A key concern is that China would punish South Korea through its influence on the Korean Peninsula with respect to North Korean threats and inter-Korean issues. A US Congress report also noted North Korea as a critical issue for South Korea to consider with respect to China's retaliation over South Korea's foreign policy: “PRC officials reportedly have said if ROK policy trends continue, Beijing will curtail cooperation with Seoul on North Korea.”Footnote ²⁰ Many interviewees pointed out exactly the same issue with respect to North Korea and China over South Korea's strategic stance that China clearly has “a lot of influence” and “a lot of leverage” in North Korea and thus South Korea might experience difficulties over important issues like “Korean unification,” “handling the North Korean nuclear issues,” and “North Korean related contingencies.”Footnote ²¹

When we asked about the capability of China to use the North Korea issue as effective leverage in punishing South Korea for balancing against China, one expert from South Korea underlined how China's influence over North Korea is crucial to South Korea: “in terms of the Korean unification, even in terms of handling the North Korean nuclear issues and North Korea related contingencies, Chinese support and Chinese involvement in those issues is essential to South Korean security and [the] South Korean future.”Footnote ²² Such perception of how influential China could be in dealing with the issue of North Korea and thus how sensitive thus costly it could be to South Korea is also shared with US experts. A former US ambassador to South Korea indicated: “I do believe that China uses North Korea to pressurize the South across a broad range of disciplines, including trade, the military, and position in the UN.”Footnote ²³ Similarly, a former US Department of State Assistant Secretary of East Asian and Pacific Affairs commented that the Moon Jae-in administration's grave concern for China's sway over North Korea influenced South Korean position on China:

We also found that there were concerns about China's retaliation in the context of latent maritime issues in the Yellow Sea. Even though there are no direct and active territorial and maritime disputes per se between South Korea and Japan, a few experts warned of the potential for China to become hostile. For instance, Chinese illegal fishing in the Yellow Sea could worsen if China intentionally remained silent or even encouraged such illegal behavior as a means of punishing South Korea for siding with the US in the US–China rivalry.Footnote ²⁵ The Air Defense Identification Zone (ADIZ) and Exclusive Economic Zone (EEZ) issues surrounding Ieodo/Socotra Rock have the potential to develop into hostile disputes between South Korea and China as well, which China could easily use to leverage against South Korea.Footnote ²⁶ One interviewee pointed out:

Another expert expressed similar concerns about potential maritime issues and claims between South Korea and China:

In sum, as there is no active and ongoing territorial and maritime dispute between South Korea and China, if South Korea would take a side with the US against China, the assessment is that South Korean governments worry that China would use issue linkage strategy to incur significant costs for South Korea to pay in other bilateral issues. Because there is no ongoing territorial and maritime disputes with China, and thus no overarching major dispute that causes regular tense relations, South Korea is more vulnerable to China as a US ally. South Korea should consider other important issues that could dominate its strategic relations with China and thus bring about costs that South Korea should avoid for the sake of its own security and national interests.

Interestingly, the difficult and costly situations that South Korea has faced and could face again with respect to China are seen differently by Korean and American experts. As former US ambassador Harry Harris paraphrased about a meeting at the Blue House: “(South Korea) wants to have an economic alliance with China and a security alliance with the United States … you [South Korea] can't have it both ways. You can have China as an economic partner … but you can't have China as an ally and expect to have us [the United States] as an ally.”Footnote ²⁹ Similarly, as another expert noted: “It's easy for the US and others to say, ‘oh, South Korea should get more involved in the South China Sea [dispute]’, but they're not going to have to pay the marginal costs that South Korea might have to pay for being more aggressive or assertive with China.”Footnote ³⁰

On the other hand, a Korean expert described well why South Korea has not considered taking any definite side in the US effort to balance China: “South Korea does not need to provoke China. I mean, we can continue our US alliance, but we can also keep our good relationship with China. [The] alliance does not mean that we should be an enemy of China.”Footnote ³¹ Similarly, and in particular focusing on our issue-focused argument, another Korean expert highlighted that: “There are issues that South Korea can and should move forward without taking a specific side, like environmental problems, climate change, technology. We can make our voice on these issues while maintaining our good alliance with the US and also being in a good relationship with China, as they are issues that all agree.”Footnote ³² Clearly there are different perspectives in South Korea and the US about the willingness and ability of South Korea to provoke China by siding with the US in balancing against China. In any case, there is consensus that South Korea is vulnerable to China.

Comparative case study: Japan

To understand South Korea's foreign policy more accurately, we provide a short comparative case study of Japan, which has an active and ongoing territorial and maritime dispute against China, while South Korea does not. China and Japan have been wrestling over islands and rocks (Senkaku/Diaoyu) in the East China Sea, with a significant amount of diplomatic, political, and even sometimes militarized incidents for decades. And there are historic animosities related to the Japanese occupation of China in the twentieth century. Since 2011, Japan has responded to China with assertive actions and by clearly siding with the US in balancing against China. Japan has a fairly hostile relationship with China over their ongoing disputes, and the tensions are already high and tangibly costly. Japan has paid relatively fewer additional costs by standing with the US against China because these two states already suffer costs resulting from their ongoing disputes against China. In other words, there are limited concerns about further intimidation and costly retaliation by China for Japan. As a result, despite moderate economic relations with China, Japan has not been as cautious about siding with the US in its rivalry with China compared to South Korea. Japan actively participates in joint military exercises, freedom of navigation operations, coordinated pressure to uphold the rule of law and respect for sovereignty, and overall, to uphold the US-led alliance system and US power projection in the Indo-Pacific.

Japan has been the most steadfast of US allies in standing with the US in its rivalry with China, going as far as willingness to help defend Taiwan against a Chinese invasion. China retaliates against Japan on occasion when it sides with the US, but these retaliations are minimally painful to Japan since there are already existing retaliations and hostilities. Thus, Japan is more willing than South Korea to side with the US in the US–China rivalry without major concerns.