AUKUS and war powers: aligning decision-making for effective defence
AUKUS has a fundamental, unaddressed challenge: the differences in how each member nation exercises its war powers.
The AUKUS security partnership—comprising Australia, the United Kingdom and the United States—has the potential to be a transformative force in the Indo-Pacific. As strategic competition intensifies in the region, the alliance is expected to enhance defence capabilities and deepen cooperation. Yet the building blocks are not aligned.
The members need to establish guidelines on the circumstances in which they’d act together militarily, and there should be a standing organisation for coordination.
While AUKUS is not a military alliance designed for joint combat operations—unlike ANZUS or the Five Power Defence Arrangements—its ability to enhance regional security depends on seamless coordination. Its objectives, particularly in deterrence and sharing advanced capability sharing, could be compromised if its members struggle to respond coherently in a crisis. A key vulnerability is the differing processes each country follows when authorising military action, potentially leading to hesitation, misalignment or even strategic paralysis.
A recent report from King’s College London, AUKUS and War Powers: The impact of constitutional constraints on military action, examines this issue in depth. The report highlights how divergent legal and constitutional frameworks across the three nations could hinder joint military action.
Each AUKUS member has a distinct approach to military decision-making, shaped by its constitutional framework and political traditions.
In Australia, the prime minister and cabinet have the authority to deploy the Australian Defence Force without parliamentary approval. While Parliament is often informed or consulted, there is no legal requirement for debate or endorsement. This system allows for rapid decision-making but limits broader democratic oversight.
In Britain, the prime minister, exercising royal prerogative, can commit forces to military operations without formal parliamentary approval. However, political norms increasingly require parliamentary debate before significant deployments, as demonstrated in 2013 when the House of Commons voted against military intervention in Syria.
Finally, in the United States, the president has broad authority to initiate military operations, but congress retains the constitutional power to declare war. While the War Powers Resolution of 1973 requires the president to notify Congress within 48 hours of deploying forces and to withdraw them within 60 days without congressional authorisation, this process has been frequently contested.
These differences create potential friction in security cooperation. The lack of a shared decision-making process could make AUKUS slow to react in a crisis, with each nation’s domestic political dynamics affecting the speed and scope of any response.
The challenge of war powers divergence is not theoretical; it has played out in recent history. The 2013 Syrian crisis illustrated how different decision-making systems can lead to disjointed outcomes. The US, under president Barack Obama, was prepared to conduct airstrikes following Syria’s use of chemical weapons, but the British parliament rejected military action. This created hesitation and weakened the credibility of the response. The delay in unified action had broader strategic consequences, emboldening adversaries and complicating Western deterrence efforts.
In an Indo-Pacific crisis, similar delays could be even more damaging. If China were to take coercive action against Taiwan or increase its activities in contested waters, AUKUS nations might struggle to coordinate an effective response. The inability to act in unison would weaken deterrence, sending mixed signals to both allies and adversaries.
For AUKUS to function effectively, its members must address decision-making challenges. While no solution will fully harmonise their constitutional constraints, practical measures can enhance coordination.
Firstly, AUKUS members could establish guidelines outlining conditions under which military cooperation would be expected. These could include specific thresholds for security threats that would trigger joint planning and response measures, even if formal approval processes differ.
Secondly, a standing coordination mechanism, such as a security council or emergency response group, could streamline communication and facilitate rapid alignment on military matters. While this body would not override national sovereignty, it could provide a framework for crisis response.
Finally, instituting a requirement for senior leaders to consult before major military deployments could ensure greater cohesion, even if parliamentary or congressional approvals are needed at different stages. This would help synchronise political messaging and strategic intent.
AUKUS is designed to deepen defence cooperation and technology sharing between Australia, Britain and the US. However, its strategic credibility depends on how well its members can navigate their war powers differences. Without clearer mechanisms for decision-making, the partnership could face operational constraints that undermine its deterrence value.
The Indo-Pacific is increasingly volatile, with rising military competition, grey-zone operations and geopolitical uncertainties. AUKUS must be more than a symbol of strategic alignment—it must be a functional and responsive initiative. Addressing the war powers gap is not just a procedural challenge—it is a strategic imperative for ensuring AUKUS can contribute to regional security.