Mutual Defence Treaty between PNG and Australia: Key Aspects
- November 24, 2025 |
- IDSA Comments
The Papua New Guinea (PNG)–Australia Mutual Defence Treaty, also known as the ‘Pukpuk Treaty’, was signed on 13 October 2025 in Canberra. It is named after the local word for crocodile in the PNG dialect. The treaty was conceived at the 31st Australia–Papua New Guinea Ministerial Forum in December 2024,[1] and consultations on it began in February 2025. In 2023, the two nations also signed a Bilateral Security Agreement to create a framework to expand cooperation on traditional and non-traditional security and capability-building, thereby strengthening Pacific-led regional security and stability.[2]
During World War II, ‘Fuzzy Wuzzy Angels’ was a term given to the Papua New Guinean soldiers who carried supplies and helped escort injured Australian soldiers to safety. Significantly, it is the first Bilateral Defence Treaty with any Pacific Island state. For Australia, it is only the third occasion that it has collaborated on a defence and security treaty in the region, after the ANZUS with the United States and New Zealand in 1951, and the AUKUS agreement with the United Kingdom and the United States in 2021.
In the Pacific Islands, China signed a Security Pact with the Solomon Islands in 2022[3] and a Comprehensive Strategic Partnership with the Cook Islands in 2025.[4] Australia, on the other hand, had vowed to step up its engagement within the Pacific family. Given these recent developments, the signing of this treaty can be seen as an initiative to strengthen its security cooperation with the Pacific Islands.[5] PNG’s commitment to this treaty lies in seeking a credible defence structure with technical and intelligence support from Australia amid increased Chinese influence. On the other hand, Canberra’s signature on this treaty is evident in its firm belief that PNG’s territory constitutes its northern border, and that, should war occur on its northern flank, it should be prepared, as noted by analysts.[6]
The Mutual Defence Treaty provides that the two nations will defend each other if either is attacked, through consultations. The other key facet of the treaty is defence cooperation, which would enhance capabilities, improve logistics interoperability, and enable collaboration with foreign militaries in response to threats within or beyond the region. It would also include joint coordinated bilateral and multilateral security exercises, information exchanges, and the sharing of intelligence.[7]
Through this treaty, PNG aims to modernise its defence capabilities and monitor its vast Exclusive Economic Zone (EEZ) with Australian support. The country lies at a critical juncture in the Indo-Pacific. It has significant mineral reserves, ranking as the 7th-largest producer of cobalt, the 16th-largest producer of copper, and the 12th-largest producer of nickel worldwide.[8] While its mineral reserves are of considerable interest to Australia, which has historically invested in its mining sector, China has also been expanding its footprint with heavy investments in the recent decade.
PNG has emphasised that China is one of its key economic partners. Talks on a Free Trade Agreement (FTA) started in 2022, and PNG also joined the Belt and Road Initiative (BRI) in 2018. China has also assisted PNG in improving the national power grid and constructing a new hospital.[9] However, PNG is well aware of its strategic proximity to the South China Sea and was also subjected to harassment in a 2024 incident that saw a Chinese drone flying unannounced into PNG territory. The treaty may thus be seen as a move to indirectly acknowledge increasing Chinese influence while still protecting PNG’s territorial sovereignty. It also creates an extra layer of security, as it hinders China from gaining a foothold through military exercises or in PNG’s political architecture.
The Pukpuk treaty, however, fails to address non-traditional security challenges, including losses of an estimated Kina 400 million annually in revenue due to illegal tuna fishing, illegal drug trafficking and emerging cyberattacks, which call for greater coordinated support in training and capacity-building for the island nation. It offers greater promise by allowing up to 10,000 Papua New Guineans to serve in Australia’s military and gives them the option to become Australian citizens. Instead of PNG’s consistent stance at ‘maintaining neutrality and avoiding any entanglement’, the treaty significantly undermines its ‘Friends to all, Enemies to None’ foreign policy approach.
Australian Defence White Papers stipulate that in the Pacific, Australia looks forward to maintaining ‘security, stability and cohesion’ and safeguarding ‘its neighbourhood from becoming any source of threat to Australia’. [10] However, it is essential to note that they have never specified the definition of which state actors/non-state actors are seen as a ‘threat’ with reference to the Pacific Region.
It is also widely accepted that a key objective of Australian Foreign policy in the Pacific Islands Region is to stay ahead of China by maintaining its ‘leader’ status, i.e., not to cede entirely to Beijing. Its counter-China strategy, as emphasised in its 2024 National Defence Strategy, aims to inhibit Chinese incursions into the security architecture of the Pacific Islands, which was later executed by signing agreements modelled on security provisions with Nauru and Tuvalu. To them, it would ensure that China wouldn’t have access to an equivalent level of infrastructure in PNG as it does in other nations. The Pukpuk Treaty can thus be seen as an extension of the earlier pacts, albeit with more provisions to support a defensive structure for PNG.
With the US withdrawing its funding for USAID in the Pacific, there is an opportunity not only for China, which has been over-amplifying its reach, but also for Australia to fill the vacuum in economic support and funding beyond grants-in-aid, something that Australia should have started doing earlier. The deal would allow Australia, along with PNG, to initiate a congruent partnership that would restore stability to the Indo-Pacific and also to formulate annual joint military exercises to demonstrate ‘strategic messaging’ and to show a capacity to be interoperable and to react to external threats instantly.[11]
For Pacific Island Nations, the treaty symbolises PNG’s growing representation in the regional security dynamic, as it asserts greater influence in shaping alliances and multilateral discussions, and also signals a shift to a more bilateral-led alignment. Internal security issues primarily characterise the Pacific Islands’ traditional security architecture. They are often dependent on foreign assistance due to their own inadequate capabilities.[12]
The Pukpuk Treaty, however, presents greater challenges, with questions about whether defence treaties are relevant to addressing the non-traditional security challenges faced by many island nations. While it does little to address PNG’s non-traditional security challenges, the treaty does create a shield against excessive influence from other countries, notably China, in its region and on the broader security architecture of the Indo-Pacific.
Mr Zeeshan Ali, Research Intern, South East Asia & Oceania Centre, MP-IDSA
Views expressed are of the author and do not necessarily reflect the views of the Manohar Parrikar IDSA or of the Government of India.
[1] “31st Australia-Papua New Guinea Ministerial Forum Communiqué”, Minister of Foreign Affairs, Government of Australia, 20 October 2025.
[2] “Australia-Papua New Guinea Bilateral Security Agreement”, Department of Foreign Affairs and Trade, Government of Australia.
[3] Joseph Hammond, “China’s Security Agreement with the Solomon Islands”, Journal of Indo-Pacific Affairs, November–December 2023, pp. 105–113.
[4] “Action Plan 2025 -2030 for the Comprehensive Strategic Partnership between the Cook Islands and the People’s Republic of China”, Ministry of Foreign Affairs, Cook Islands.
[5] Joanne Wallis, “Contradictions in Australia’s Pacific Islands Discourse”, Australian Journal of International Affairs, Vol. 75, No. 5, 2021, pp. 487–506.
[6] Ian Kemish, “With New PNG Defense Treaty, Australia is Delivering on Its Rhetoric About Trust at a Critical Time”, The Conversation, 15 September 2025.
[7] “Papua New Guinea – Australia Mutual Defense Treaty”, Department of Foreign Affairs and Trade, Government of Australia.
[8] “Papua New Guinea Country Commercial Guide”, International Trade Administration, Department of Commerce, United States of America.
[9] Barbara Barkhausen, “Papua New Guinea: Friend to All, Enemy to None”, IPS Journal, 15 June 2023.
[10] Joanne Wallis, “Contradictions in Australia’s Pacific Islands Discourse”, no. 5.
[11] Sam Roggeveen, “The Pukpuk Treaty is About Keeping China at Bay, Not Military Strength”, The Interpreter, 7 October 2025.
[12] “Security Cooperation in the Pacific Islands”, Stretton Institute, University of Adelaide.
