The Expansion of Orient Shield 26 and Reduction of US-ROK Exercises: Realigning the Indo-Pacific Alliance Burden and South Korea’s Policy Space

Executive Summary

The concurrent expansion of the trilateral U.S.-Japan-Australia exercise 'Orient Shield 26' and the shortening of combined U.S.-ROK exercises (from 11 to 5 days) signal an asymmetric realignment of the U.S. burden-sharing structure in the Indo-Pacific, which is expanding along the Japan-Australia-India axis while contracting along the U.S.-ROK axis. This appears to be the result of the Trump administration's National Defense Strategy—which articulated the principle that the U.S. 'cannot bear the burden alone'—being applied differentially based on each ally's capacity for military contribution. The U.S.-ROK axis seems to have been targeted for adjustment due to the limited utility of its defense structure, which is specialized for countering North Korea. China has labeled this expansion of a lattice-like network as 'bloc politics,' but is employing a regionally differentiated response: harsh criticism toward the Philippines, but parallel dialogue channels on the Korean Peninsula, such as Foreign Minister Wang Yi's visit to Seoul. The fact that the Freedom Edge exercise proceeded as scheduled even as U.S.-ROK exercises were downsized suggests that trilateral U.S.-ROK-Japan cooperation and bilateral burden-sharing adjustments are operating on separate tracks. However, the potential remains for this to escalate into an issue of extended deterrence credibility. South Korea requires a dual strategy: avoiding an over-interpretation of the exercise reduction as a sign of abandonment, while simultaneously managing the effectiveness of the Nuclear Consultative Group (NCG) and opportunities to diversify its defense exports.

I. Situational Analysis

Expansion of Orient Shield 26: U.S.-Japan-Australia Exercises and Deepening U.S.-China Strategic Competition

1. Background and Developments

The trilateral U.S.-Japan-Australia joint military exercise 'Orient Shield 26' is being held from September 8 to 24 [1]. The Global Times described the exercise as a repackaging of "bloc politics" under the pretext of enhancing interoperability [1]. An editorial stated that the exercise is an example of "injecting confrontation, forward-deployed firepower, and bloc politics into an already fragile Asia-Pacific security environment" [1].

This expansion is not an isolated event. The Brookings Institution has analyzed that the Trump administration's National Defense Strategy explicitly states the logic that "the United States has dispersed resources, faces simultaneous real threats, and cannot bear all the burdens alone" [3]. This strategy demands greater spending and larger regional responsibilities from allies [3]. The expansion of Orient Shield 26 is an instance of this structural policy being implemented along the Japan-Australia axis.

Japan's institutional foundations are also aligned with this trend. Following the revision of its Three Principles on Transfer of Defense Equipment and its decision to acquire counterstrike capabilities, Japan has been expanding military cooperation not only with the United States and Australia but also with India. The Japan Air Self-Defense Force (JASDF) is conducting the 'Veer Guardian 26' exercise with the Indian Air Force in Rajasthan, India, from September 9 to 21 [7]. JASDF Chief of Staff Takehiro Morita described the exercise as a "valuable opportunity to promote mutual understanding and trust" [7]. Defense Minister Koizumi met with Indian Defence Minister Rajnath Singh and pledged to deepen defense cooperation [7]. This is highly symbolic as it marks the first deployment of Self-Defense Forces fighter jets to Indian territory [8].

Conversely, a trend of burden reduction has appeared on the U.S.-ROK axis. The two countries agreed to shorten their annual joint military exercises from 11 to 5 days and to scale back some field training exercises [4]. This measure follows President Trump's directive to significantly reduce U.S. military participation [4]. The announcement coincided with the visit of Chinese Foreign Minister Wang Yi to South Korea [4].

2. Current Situation

In a separate editorial, the Global Times also took aim at the 75th anniversary of the U.S.-Philippines Mutual Defense Treaty [2]. Since the inauguration of the Marcos administration, the Philippines has continuously expanded its defense agreements with the U.S. under the banner of 'military modernization.' The frequency of joint exercises, the number of bases accessible to U.S. forces, maritime patrols, and intelligence cooperation have all increased [4][2]. Beijing's criticism focuses less on the military substance of the exercises and more on the way the U.S. is consolidating bilateral relationships into a multilateral network.

The U.S., ROK, and Japan are continuing separate cooperation amidst the trend of reduced exercises. The three countries are conducting the 'Freedom Edge' exercise, aimed at North Korea, in international waters southeast of Jeju Island from September 7 to 11 [14][11]. Local media have covered this exercise as an example of ongoing trilateral defense cooperation even after President Trump ordered the reduction of U.S.-ROK exercises [11].

U.S.-led multilateral exercises have also expanded in Southeast Asia. Fifteen countries participated in the 'Super Garuda Shield' hosted by Indonesia [9]. An Indonesian government official explained that the exercise was a balancing act intended "not to provoke" Beijing [9]. This shows that the expansion of U.S.-led multilateral exercises is not being received uniformly across the region.

Foreign Policy reported that in July, China launched a submarine-launched ballistic missile (SLBM) from the South China Sea into the Pacific, which flew over the Philippines and landed in the waters south of Guam [13]. The projectile landed within the South Pacific Nuclear Free Zone [13]. This can be interpreted as a demonstration of China's military response capabilities to the expansion of U.S.-led exercises.

3. Key Actors and Positions

United Statesis making a structural choice to transfer regional responsibilities to its allies in line with its National Defense Strategy [3]. President Trump directly ordered the scaling down of U.S.-ROK exercises [4]. Simultaneously, it is condoning or leading the expansion of multilateral exercises along the Japan-Australia-India-Philippines-Indonesia axis. This is a method of differentiating resource allocation based on regional threat perceptions, allied capabilities, and the potential for engagement with China.

Japanis leveraging the easing of its defense policy constraints to diversify its partners beyond the U.S. and Australia to include India [7][8]. Prime Minister Sanae Takaichi has proposed strengthening supply chains as an evolution of the 'Free and Open Indo-Pacific' concept [15]. This suggests that Japan's Indo-Pacific strategy is expanding to encompass both military cooperation and economic security.

Chinais framing the expansion of exercises as "bloc formation" and is varying the intensity of its criticism by region. The Global Times addressed Orient Shield 26 and the U.S.-Philippines defense treaty in separate editorials, repeatedly applying the same "bloc politics" frame [1][2]. In contrast, it has also shown an unpredictable response pattern, such as offering only a brief, dismissive comment on Taiwan's Han Kuang exercises, calling them a "wasteful show" [5]. This indicates that Beijing is strategically adjusting the intensity and timing of its response on a case-by-case basis.

South Koreais in an asymmetric position with the reduction of U.S.-ROK exercises. The overlap between Minister Wang's visit to Seoul and the announcement of the exercise reduction was interpreted by local media as a signal to encourage dialogue [4]. At the same time, trilateral U.S.-ROK-Japan exercises like Freedom Edge are being maintained [14][11], so it is premature to simplify this as a signal of abandonment.

Philippines and Indonesiaare pursuing different hedging strategies. The Philippines, under the Marcos administration, is actively expanding defense cooperation with the U.S. [4], whereas Indonesia is maintaining a balancing act, hosting multilateral exercises while trying to avoid provoking Beijing [9].

4. Key Issues

The first issue is that the U.S. method of resource allocation is creating contradictory signals in different regions. An asymmetry is emerging simultaneously: expansion along the Japan-Australia-India axis and reduction along the U.S.-ROK axis [4][7][1]. This should be seen not as a single, consistent strategy from Washington, but rather as a differential allocation based on regional threat priorities and allied capabilities.

The second issue is that China's response targets the framing of these activities more than their military substance. Beijing defines the very structure of the U.S. consolidating bilateral relationships into a multilateral network as "bloc formation," rather than focusing on the scale or content of individual exercises [1][2]. This frame is being applied with varying intensity depending on the region, such as Taiwan, the Philippines, and Northeast Asia [5][1][2].

The third issue is South Korea's positioning. Simplifying the reduction of U.S.-ROK exercises as a signal of abandonment would overlook the reality that U.S.-ROK-Japan cooperation is continuing in parallel [14][11]. Conversely, completely ignoring it could delay a response to the structural change of resource reallocation. Independently tracking the pace and nature of expanding minilateral networks, such as U.S.-Japan-Australia and U.S.-Japan-India, will likely be a prerequisite for future policy judgments.

II. In-Depth Analysis

The Expansion of Orient Shield 26 and U.S.-China Strategic Competition: A Deeper Structural Analysis

1. Root Cause: Resource Constraints and the Institutionalization of Burden-Shifting

The root cause of this asymmetric expansion and reduction lies in the limits of U.S. physical resource allocation. The Brookings Institution has analyzed that the Trump administration's National Defense Strategy explicitly contains the logic that "the United States has dispersed resources, faces simultaneous real threats, and cannot bear all the burdens alone" [3]. Although this document was released with little fanfare, its implications are structural [3]. It means that the policy of demanding more spending, greater military contributions, and larger regional responsibilities from allies has been formalized at the policy document level [3].

The reason this logic has been applied differently by region is the variance in each ally's capacity for military contribution. Japan has expanded its independent power projection range through the revision of its Three Principles on Transfer of Defense Equipment and its decision to acquire counterstrike capabilities. The first deployment of JASDF fighter jets to Indian territory is a case of this capacity being realized [7][8]. Australia is also strengthening its submarine and missile capabilities under the AUKUS framework, which lowers the relative burden for the U.S. in expanding exercise scales. In contrast, the U.S.-ROK axis has long maintained a defensive exercise structure specialized for the singular threat of North Korea, and this structure is difficult to repurpose for broader deterrence missions such as in the Taiwan Strait or the South China Sea. Underlying President Trump's direct order to shorten U.S.-ROK exercises from 11 to 5 days and significantly reduce participation is Washington's assessment of the utility of such a mission-specialized alliance [4].

2. Structural Context: Realignment of the Security Architecture

2.1 Security Structure: From Bilateral Alliances to a Lattice-like Network

The Indo-Pacific security architecture is transitioning from a hub-and-spokes model of bilateral alliances (U.S.-Japan, U.S.-Australia, U.S.-ROK) to a lattice-like network. Japan's military cooperation with India, the trilateralization of Orient Shield, and the institutionalization of the trilateral Freedom Edge exercise are individual nodes in this transition [7][11][14]. This realignment is characterized by the U.S. maintaining its hub role while increasing horizontal linkages among allies to distribute its own burden. Japan's pragmatic course of simultaneously expanding separate minilateral exercises with India and Australia, in addition to the U.S., can also be explained within this structure [8].

This realignment does not undermine trilateral U.S.-ROK-Japan cooperation itself. The three countries are scheduled to proceed with the North Korea-focused 'Freedom Edge' exercise in international waters southeast of Jeju Island from September 7 to 11, even as bilateral U.S.-ROK exercises are being downsized [14][11]. This shows that adjustments to the bilateral burden and the maintenance of trilateral minilateral cooperation are moving on separate tracks. The question of the effectiveness of the Nuclear Consultative Group (NCG) arises at this juncture. It remains to be seen whether the trend of reducing U.S.-ROK exercises will escalate into a credibility issue for the extended deterrence commitment or remain merely an adjustment for mission reallocation.

2.2 Political Structure: China's Differentiated Framing Response

China's reaction is less a military threat assessment and more a response to political framing. The Global Times characterized Orient Shield 26 as an instance of "injecting confrontation, forward-deployed firepower, and bloc politics into an already fragile Asia-Pacific security environment" [1]. A separate editorial criticized the 75th anniversary of the U.S.-Philippines Mutual Defense Treaty in the same context [2]. The common thread in both editorials is that they problematize the "multilateral networking of bilateral relationships" itself, rather than the force scale or operational content of the exercises.

This frame is employed differently by region. Toward the Philippines, it took the form of questioning the historical legitimacy of the military alliance itself (in the 75th-anniversary editorial), while toward the U.S., Japan, and Australia, it directly refuted the justification for expanding the new exercise [1][2]. In the Taiwan Strait and Western Pacific, Beijing has also employed tactics to increase unpredictability, such as refraining from immediate response drills and instead issuing brief, dismissive statements like calling them a "wasteful show" [5]. This suggests that Beijing operates a dual-track response system, using discourse warfare and tactics of military ambiguity differently according to the regional situation.

2.3 Economic Structure: Hedging Linked to Nickel and Supply Chains

The responses of Southeast Asian countries cannot be explained by security logic alone. While participating in the U.S.-led 'Super Garuda Shield' with 15 other nations [9], Indonesia also conducted joint exercises with Chinese naval vessels coinciding with Taiwan's Han Kuang exercises [5]. Behind this dual track lies an economic structure in which China has supplied a significant portion of the capital and technology needed for Indonesia's nickel downstreaming policy [5]. The fact that Indonesia's defense minister directly requested an expansion of joint exercises in a meeting with his Chinese counterpart shows that security cooperation is intertwined with economic interdependence [5]. This combined economic-security structure is likely to develop not uniformly across other ASEAN countries like the Philippines and Vietnam, but in a fragmented manner depending on each country's degree of economic dependence on China [5].

3. Comparison with Historical Precedents

3.1 Similarities with Cold War Debates on Forward Defense Burden-Sharing

The logic of shifting burdens to allies is not a new phenomenon. During the Cold War, the U.S. continuously demanded that its European and Asian allies increase their defense cost-sharing, a pattern repeated since the Nixon Doctrine. However, what distinguishes the current situation is that burden-shifting is not being applied uniformly across the entire region but is differentiated according to each ally's capacity for military contribution. Whereas Cold War burden-sharing debates primarily revolved around defense spending ratios, the current issue is manifesting through tangible indicators like the scale and duration of exercises, giving it a greater symbolic impact on public opinion in allied countries.

3.2 Contrast with the Obama Administration's Rebalance Policy

The Obama administration's 'pivot to Asia' policy involved the U.S. directly reallocating its own resources to the Indo-Pacific region. The current situation is different in that the U.S. is instead trying to fill gaps by expanding the roles of its allies rather than reallocating its own resources. This also connects to the vacuum in the Western Pacific left by the departure of U.S. carrier strike groups due to the prolonged Iran war, as identified in a previous EAI analysis. It means that the physical limitation of being unable to cover two theaters simultaneously with a robust posture is a structural constraint that is repeatedly appearing not only in carrier deployments but also in the current realignment of exercises [5].

3.3 Repetition of the Pattern of Expanding Philippine Defense Agreements

Since the inauguration of the Marcos administration, the Philippines has continuously expanded its defense agreements with the U.S. across the board, including the frequency of joint exercises, the number of bases accessible to U.S. forces, maritime patrols, and intelligence cooperation [4][2]. The fact that this pattern has been proceeding independently of the expansion of Orient Shield 26 shows that the current situation is not an entirely new directional shift but an extension of existing trends. However, there is a difference: while the Philippine case is focused on the single dispute point of the South China Sea, Orient Shield has expanded in character to become a broad, multilateral network encompassing Japan, Australia, and India.

4. Key Variables Shaping Future Developments

The first variable is whether the credibility of extended deterrence will be substantively tested. The key question is whether the reduction of U.S.-ROK exercises will be a one-time adjustment or lead to further force realignments and exercise reductions. The coincidence of Chinese Foreign Minister Wang Yi's visit to Seoul with the announcement of the exercise reduction [4] suggests that Beijing may interpret this adjustment as a sign of a loosening U.S.-ROK alliance. If this interpretation solidifies, it could lead to changes in China's approach to the Korean Peninsula.

The second variable is the pace of Japan's expansion of its minilateral networks. Prime Minister Takaichi's proposal to strengthen supply chains as an evolution of FOIP [15] shows that Japan's Indo-Pacific strategy is shifting from purely military cooperation to a model that combines economic and security elements. If this combination deepens, Japan-led minilateral cooperation could have a different threshold for entry than a military alliance, potentially widening the room for participation by middle powers, including South Korea.

The third variable is the sustainability of ASEAN countries' hedging strategies. If Indonesia's dual-track approach is based on its dependence on the nickel supply chain [5], it is likely that participation in U.S.-led multilateral exercises and the expansion of military cooperation with China will continue in parallel as long as this structure persists. This implies that the bloc-based network the U.S. is promoting is unlikely to become a fully exclusive bloc in Southeast Asia, a point worth considering when designing South Korea's regional engagement strategy.

The fourth variable is the balance between China's discourse warfare and its tactics of military ambiguity. A key indicator for future tension levels will be whether Beijing continues its parallel approach of direct criticism of Orient Shield and the Philippine defense treaty [1][2] alongside a restrained response in the Taiwan Strait [5], or whether its discourse warfare in a specific region transitions into a military response.