A next-generation agenda: South Korea-US-Australia security cooperation

Atlantic Council (Scowcroft Center for Strategy and Security) Indo-Pacific Security Initiative

https://video.wixstatic.com/video/956d73_3a77db3ca7c54aecbab3fbbda057df8e/1080p/mp4/file.mp4

I'm excited to announce that my co-authored Atlantic Council Scowcroft Center for Strategy and Security issue brief, "A Next-Generation Agenda for South Korea-US-Australia Security Cooperation," is officially launched! 🇰🇷 🇺🇸 🇦🇺

This morning, I had the privilege of participating in a virtual event that explored the challenges and opportunities for deepening collaboration among South Korea, the US, and Australia, addressing both traditional and non-traditional security issues.

It’s been a true honour to work alongside my amazing co-authors, Lauren Gilbert and Kester Abbott, on this issue brief over the past few months. Plus, thanks to Eunju Oh for joining today's event as a programme participant. A big shout-out to the Atlantic Council Scowcroft Center for Strategy and Security, including Markus Garlauskas, Lauren, Emily Kim and their team and The Korea Foundation for making this possible. Congratulations to all contributors involved in the publication 👏

You can watch the full recording of today’s event: https://www.youtube.com/live/_dj8A0UWIfI

Please note, I have shared these thoughts in a personal capacity, and my views do not reflect those of my organisation.

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This speech delivered was at "A next-generation agenda for South Korea-US-Australia security cooperation Issue Brief Launch event" on 6 November 2025, hosted by Atlantic Council.

Thank you for your kind introduction. Hi, I’m Hannah Heewon Seo, co-author of the issue brief, joining from the spiritual heart of Australia, Uluru.

Before sharing my thoughts, I would like to clarify that I am speaking in a personal capacity, and my views do not represent those of my organisation.

I’d want to begin by reflecting on the significant moment of regional order from last week.  APEC 2025 in Gyeongju marked an important milestone that underscored South Korea's return to the international community, as President Lee Jae-myung proclaimed at the UN General Assembly in September.

The key question now is how South Korea can maintain — and even build on — this momentum with its long-standing allies, the United States and Australia. Our issue brief offers timely and practical policy recommendations toward that goal.

It outlines some of the challenges that the three countries face, and I would like to highlight two key challenges in particular.

First, differences in threat perception

Geography shapes security priorities. Inevitably, North Korea shares South Korea’s security focus, especially when tensions remain elevated, as they are now. Australia, meanwhile, expresses its concern over China’s military expansion in the Taiwan Strait, South China Sea and heightened naval activities in Australia’s exclusive economic zone. The US is well-positioned to manage the challenges posed by both North Korea and China.

In today’s environment, with the growing China-Russia-North Korea Security axis, comprising a Comprehensive Strategic Partnership alongside Washington’s relative decline in influence in Asia and its “America First” tendencies, even mild misalignment could undermine the sustainability of trilateral cooperation.

Second, contrasting risk tolerance with China

Here, the difference is stark between Australia and South Korea. Australia has been demonstrating a more proactive security posture through AUKUS. South Korea has been more cautious about publicly choosing a side between the US and China, particularly after the 2016 deployment of the Terminal High-Altitude Area Defence and significant economic retaliation. That said, one of the surprises from APEC may indicate a shift: President Lee’s request — and President Trump’s approval — for South Korea to develop nuclear-powered submarines. Whether this materialises will be an essential indicator of Seoul’s strategic direction, especially in balancing relations with China.

Let’s now turn to opportunities — and this is where the trilateral security cooperation can truly distinguish itself.

The most important message from our issue brief that I personally like to highlight is that this trilateral cooperation must establish legitimacy beyond the three countries across the Indo-Pacific.

South Korea and Australia often frame themselves as middle powers, which is valid relative to the US; however, within the Indo-Pacific, both are advanced, capable, and influential states. They have the capacity to shape regional norms and contribute to shared security as proactive security providers.

Therefore, this trilateral arrangement should not be perceived merely as a bloc responding to great-power competition, but rather as a trusted partner contributing to an inclusive and stable regional order.

To achieve this, three countries should seek areas where opportunities lie, and I have focused on non-traditional security issues in this issue brief.

Nontraditional security issues and their solutions offer the most practical starting points for trilateral cooperation. These challenges require multilateral solutions, offer lower political risk, and provide credible alternatives to China’s ambitious Belt and Road Initiative, enabling the effective leverage of assistance and soft power across the Indo-Pacific region.

This is particularly relevant in Southeast Asia and the Pacific Islands, where China has been most active — and where all three partners bring complementary strengths:

-             South Korea, through ASEAN+3,

-             Australia, through the Pacific Islands Forum, under the theme of “Pacific Family” and

-             The US, through deterrence capabilities that neither South Korea nor Australia can independently provide.

The trilateral must respond directly to local priorities. Climate resilience and disaster preparedness consistently emerge as the most urgent, hence legitimate areas for cooperation. Both Southeast Asia and the Pacific Islands are among the world’s most climate-vulnerable regions.

Our issue brief proposes three concrete recommendations for developing disaster-resilient infrastructure projects and early warning systems:

First, A cloud-based disaster monitoring system, linked to ASEAN and Pacific mechanisms, to track natural disasters such as floods, droughts, and wildfires.

Second, Capacity-building initiatives, including joint academies, exchange programs, and fellowships.

And third, Joint infrastructure resilience guidelines to support sustainable development.

Together, these initiatives provide tangible and community-level benefits, demonstrating the trilateral’s constructive security role on issues that matter most to regional neighbours.

South Korea–US–Australia trilateral cooperation remains an evolving framework — in many ways, a blank canvas. This presents us with a rare opportunity to explore the full potential of the forward-looking security agenda that can be achieved together and carried forward into the next generation.

To finish off, I would like to sincerely thank the Atlantic Council and the Korea Foundation for providing this opportunity. I also extend my warm congratulations to my fellow co-authors, Lauren and Kester and the contributors to the publication of this issue brief. Thank you.

a-next-generation-agenda-for-south-korea-us-australia-security-cooperation.pdf

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