Australia’s Pacific diplomacy has lessons – and limits – for South 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.