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South Korea, explained.
The broader lesson for Seoul is not to replicate Australia’s Pacific strategy geographically, but to adopt its underlying logic of networked defence diplomacy (Brenton Freind/Defence Imagery)
Canberra’s web of regional security deals shows how South Korea could diversify beyond Washington within an alliance framework.
Australia’s Pacific diplomacy has lessons – and limits – for South KoreaAustralia’s Pacific diplomacy has lessons – and limits – for South Korea
About the author
Gabriela Bernal
Dr Gabriela Bernal is a Korean affairs analyst based in Seoul, South Korea, and a Non-Resident Fellow at the European Centre for North Korean Studies.
South Korea’s middle-power diplomacy is entering a period of reassessment (Opens in new window). Most concern is centred around questions (Opens in new window) about US security commitments, declining (Opens in new window) leverage over Pyongyang, and a push (Opens in new window) for greater defence autonomy. President Lee Jae-myung has framed (Opens in new window) his foreign policy around the concept of “pragmatic diplomacy”, seeking to preserve the US alliance while expanding Seoul’s diplomatic flexibility and strengthening relations with key partners.
To this end, Australia’s Pacific diplomacy strategy could offer valuable lessons for Seoul.
While Canberra remains firmly anchored to its alliance with the United States, it has simultaneously built an extensive network of bilateral security partnerships throughout the Pacific. This strategy (Opens in new window) has accelerated over recent years, with Australia concluding security agreements with Papua New Guinea, Tuvalu, Nauru, and Vanuatu.
The Ocean of Peace Alliance (Opens in new window) signed this month makes Fiji Australia’s fourth formal treaty ally, along with PNG, New Zealand and the United States. Unlike most of the other Pacific agreements focused primarily on capacity-building or policing, the Fiji treaty includes mutual defence obligations in response to armed attacks within the Pacific.
The broader lesson for Seoul is not to replicate Australia’s Pacific strategy geographically, but to adopt its underlying logic of networked defence diplomacy.
A more networked approach could also reduce, though not eliminate, South Korea’s dependence on the United States.
South Korea has already begun taking tentative steps in this direction: it has institutionalised trilateral cooperation (Opens in new window) with Washington and Tokyo through the Camp David framework, deepened (Opens in new window) engagement with Southeast Asia via the Korea–ASEAN Solidarity Initiative, and pledged (Opens in new window) expanded maritime cooperation with the Philippines. Together, this offers a foundation for a wider network of partnerships, built incrementally rather than from scratch.
In addition to its long-held bilateral deterrence security framework anchored in the US–ROK alliance, Seoul could expand defence cooperation with key regional actors including Japan, Australia, the Philippines, Vietnam, Singapore and potentially selected Pacific Island countries. This could be achieved through defence dialogues, intelligence sharing, defence-industrial cooperation, maritime security assistance and regular joint exercises. Such arrangements would not necessarily constitute formal alliances, but they could gradually build a web of relationships that increases South Korea’s diplomatic influence while more broadly distributing regional security responsibilities. South Korea has also emerged as one of the world’s leading (Opens in new window) arms exporters, providing military equipment to countries in Europe, Australia and several Southeast Asian states. Integrating defence exports with long-term security partnerships could also allow Seoul to transform commercial defence relationships into broader strategic partnerships.
A more networked approach could also reduce, though not eliminate, South Korea’s dependence on the United States. The US alliance would remain the cornerstone of South Korean security, particularly given North Korea’s nuclear capabilities. However, diversified security relationships would provide greater resilience during periods of uncertainty in Washington while demonstrating that South Korea is a regional security contributor. This objective aligns closely with Lee Jae-myung’s emphasis on pragmatic diplomacy and greater autonomy without abandoning the alliance framework.
Such a strategy could also help offset the deepening – if informal – coordination among North Korea, Russia and China with a dense web of middle-power partnerships building collective resilience,short of a direct counter-alliance.
South Korea‘s President Lee Jae-myung and First Lady Kim Hye-kyung this month (Park Dae-jin/Republic of Korea)
The benefits of expanding defence partnerships are real, but Australia’s experience also reveals the limits of such a strategy. For all its treaty-making, Canberra has not displaced (Opens in new window)China’s influence in the Pacific, and Pacific island governments are selective (Opens in new window) as external powers compete for their alignment. The pace of these deals has also drawn criticism closer to home: Pacific civil society groups warn (Opens in new window) that the region’s Ocean of Peace concept, originally framed around locally led peacebuilding, is being redirected toward externally driven deterrence against China – a reminder that a widening network can mask shallow legitimacy.
South Korea faces a further constraint: lacking Australia’s geographic advantage, it must keep most of its diplomatic and military resources fixed on the immediate North Korean threat, leaving relatively less bandwidth for sustained regional engagement. The partners differ, too. Australia extends guarantees to small, dependent states, while Seoul’s would-be partners are mostly middle powers with relatively strong militaries, making for looser, less binding cooperation among peers rather than the more asymmetric relationships that dominate the Australian approach.
Domestic politics further compound the difficulties. Although defence cooperation with Japan has continued under Lee, he has called (Opens in new window) an Acquisition and Cross-Servicing Agreement with Tokyo “practically necessary” yet unfeasible for now given unresolved historical grievances (Opens in new window).
Seoul’s sharp partisan (Opens in new window) swings (Opens in new window) also undercut the continuity that durable partnerships require, compared with Australia’s relatively (Opens in new window) consistent (Opens in new window) policy on the Pacific islands across recent administrations.
Another key issue is China. While Australia’s strategy is aimed primarily at constraining Chinese influence in the region, a South Korean-led network aimed, however implicitly, at weakening Chinese interests could backfire. China is South Korea’s largest trading partner, a treaty ally of North Korea, and has previously proven its willingness to punish (Opens in new window) Seoul harshly over military moves it deems threatening. Seoul would therefore need to frame any expansion of its defence partnerships as broadly defensive rather than aimed at containing a single power – a delicate balancing act.
Even a modest, carefully calibrated version of Australia’s Pacific diplomacy – deeper defence dialogues, intelligence sharing and joint exercises with willing partners – could expand Seoul’s strategic options, distribute regional burdens, and establish it as a more consequential Asia-Pacific actor in the long term.
