The next National Defence Strategy (NDS), expected in early 2026, should deliver something Australia has long lacked: a strategic narrative that tells the public what truly matters to our security, what threatens it, and how Defence will protect it. With no new major National Security Strategy since 2013 or a foreign policy white paper since 2017, the NDS now shoulders the weighty burden of defining Australia’s national interests.
Because the NDS must speak for both security and defence, it needs to clarify and strengthen the two core tenets of any strategy: Australia’s vital national interests and the threats that endanger them.
Australia can no longer rely on vague ‘security’ or ‘stability’ to justify multi-decade military investments. When the government asks Australians to support major investments—nuclear-powered submarines, a guided weapons enterprise, hardened northern bases and a larger defence workforce—it must explain their logic, not assume it. The public should be able to easily appreciate what risks justify these costs, what interests are at stake, why these capabilities matter and why they are needed now.
A strategy that cannot be explained is a strategy that’s unlikely to be sustained—and today the stakes are too high for ambiguity. Without that clarity, government lacks a foundation to build the social licence needed for long-term investment. With it, Australians can more easily see what we are preparing for, why it matters and what trade-offs will be required. A strategy that links interests, risks and resources sharpens policy, elevates public debate and strengthens Australia’s ability to act with purpose—both today and in the decade ahead. Strategy begins with an assessment of the environment.
When the 2025 Annual National Threat Assessment was released last February, the director-general of security, the head of the Australian Security Intelligence Organisation, put it bluntly: ‘Australia has never faced so many different threats at scale at once … Australia is facing multifaceted, merging, intersecting, concurrent and cascading threats.’ The 2025 threat assessment further declassified ASIO’s outlook to 2030 to explain the threats Australia and Australians are facing. As a society we need to consider how we respond to these significant challenges.
And while the report clearly detailed the threats we face at home, we still lack a clear explanation for how the behaviour and actions of other nations are threatening our vital interests from afar.
The 2024 NDS also analyses our strategic circumstances, but it does not clearly connect them to our national interests, nor them to our defence policy, posture and capability requirements. It touches on these components but never links them in a compelling narrative that establishes what threatens us, what we care about, what outcomes we must protect or advance, and what capabilities are essential.
Until the Australian public understands why these threats matter, how are they expected to support the policy choices required to fund them? Leaders often speak of national interests, but it’s likely that few Australians could clearly define them. That’s because they are enduring, and aspirational as to what we seek to preserve or advance around security, prosperity, and an Australian way of life. They are guideposts that promote action.
Vital national interests are the narrower set of interests that must be protected at all costs because their loss would fundamentally endanger Australia’s survival or sovereignty. Protecting the security of Australia and its people is core to this, but in today’s world these interests are more complex as are the varied threats to them. Articulating our vital interests is more than a bureaucratic exercise; it is a democratic necessity.
The 2024 NDS does not explicitly identify vital interests, though many can be inferred. For example, it says Australia’s interests lie in the ‘protection of our economic connection to the world’. Yet, the strategy never explains which threats endanger that economic connection, nor which of the NDS’s prioritised six capability effects or the six immediate priorities contribute to protecting it. Instead, threats are gripped up together under a ‘strategy of denial’ to deter actions against all threats to Australia’s interests. This only raises further questions: which interests, whom are we seeking to deter from what threat, and do we have the capabilities for such deterrence?
Effective deterrence rests on the premise of discouraging the threatening actor from taking an unwanted action by influencing their decision-making calculus to not take an action. If we are deterring all threats all at once, we are likely to be deterring nothing. Deterrence succeeds when the potential aggressor refrains from acting because it assesses the likelihood of achieving its aim is too low or the costs of acting are too high.
Which threats does Defence prioritise as vital enough to deter and which capabilities are essential to protecting them?
Clear signals of commitment to defined interests and expressions of resolve are fundamental inputs to shaping the perceptions and calculations of potential aggressors. The 2026 NDS will be a significant opportunity to address this gap. The current NDS lists goals, risks, tasks and capabilities, but it never squarely defines what Australia’s vital interests are or how each defence investment is expected to protect them.
This missing narrative—the logic that runs from interest to threat to policy—leaves Australians unclear about what risks we are preparing for, why certain capabilities matter, and whether we are over- or under-investing in key areas. Right now, the public sees submarines, long-range missiles and basing as isolated, expensive projects that compete with other social priorities, not as crucial means to preserving Australia’s vital national interests.
If Australia is to be ready for the decade ahead, the next NDS must finally tell the nation what matters, what threatens it, and how we intend to safeguard Australia’s vital interests in this worsening security environment.
This article was originally published in The Canberra Times.