A senior researcher form the Royal Academy of Cambodia has suggested an unusual strategy to resolve the conflict in Ukraine: A Commonwealth Defence Treaty. AI
As the war in Ukraine continues, the international community faces difficult questions about how to maintain global stability and protect sovereign nations from aggression.
With the US increasingly focused on an “America First” policy and prioritising domestic issues and its relationship with Israel, and the EU facing economic and political challenges that limit its ability to provide long-term military support, a significant gap in global security has emerged.
In this context, the Commonwealth of Nations — an organisation comprising 56 member states — stands as an underutilised yet promising vehicle for global security.
By transforming itself into a military alliance, the Commonwealth could play a crucial role in safeguarding Ukraine and deterring future aggression from Russia.
The Commonwealth has traditionally been seen as a voluntary association focused on shared values such as democracy, human rights and economic cooperation.
However, in the face of growing global threats, there is a strong argument for it to adopt a collective defence framework similar to NATO.
Given that the UK — the Commonwealth’s founding member — has already emerged as a leading supporter of Ukraine, this transformation would not only be logical but also strategically advantageous.
With other major powers such as Canada, Australia, India and South Africa as members, the Commonwealth has the economic and military potential to form a robust security alliance capable of countering external threats.
At the heart of this transformation could be the establishment of a Commonwealth Defence Treaty (CDT) — a formal agreement that binds member states to defend each other against aggression.
Similar to NATO’s Article 5, the CDT would create a mutual defence clause, ensuring that any attack on a Commonwealth member would be met with a collective military response. This would immediately extend a powerful deterrent against Russia and other potential aggressors.
Transforming the Commonwealth into a military alliance would offer several strategic benefits.
First, it would provide Ukraine with an immediate security umbrella, reducing its vulnerability to Russian aggression.
Second, it would enhance the UK’s global influence post-Brexit by positioning it as the leader of a major security bloc.
Third, it would establish a new balance of power, offering an alternative to NATO and reducing reliance on the US, which is increasingly focused on domestic concerns and the Indo-Pacific region.
A Commonwealth Defense Treaty could also address modern security challenges beyond conventional warfare. This would include protection against cyberattacks, economic coercion, and disinformation campaigns — tactics frequently employed by Russia.
By fostering greater military interoperability among member states, the CDT could respond swiftly to emerging threats.
Despite its potential, establishing a Commonwealth military alliance would face several political and logistical challenges.
Countries like India and South Africa, which maintain close diplomatic and economic ties with Russia, may be reluctant to join a military pact that directly confronts Moscow.
Smaller Commonwealth members, particularly those in the Caribbean and Pacific regions, may also struggle to meet defence spending commitments.
Moreover, the US may view a Commonwealth alliance as a competitor to NATO, which could strain transatlantic relations.
However, these challenges can be addressed through phased implementation. For instance, bilateral defence agreements between the UK and Ukraine could serve as the foundation for broader Commonwealth participation.
Smaller states could receive financial assistance from a newly created Commonwealth Defence Fund, allowing equitable contributions without overburdening their economies.
One of the most compelling arguments for a Commonwealth military alliance is its potential to prevent World War III. If Russia perceives Ukraine as part of a formidable defence network, the risks and costs of further aggression will rise significantly.
A clear deterrence strategy — supported by nuclear powers like the UK — could discourage further escalation.
Conversely, failing to act may embolden Russia and other revisionist powers, leading to further destabilisation in Europe and beyond.
By stepping into the security vacuum left by US retrenchment and EU limitations, the Commonwealth could play a critical role in maintaining global peace.
The Commonwealth of Nations is at a crossroads. It can remain a symbolic association or evolve into a dynamic force for global security.
By establishing a Commonwealth Defence Treaty, the organisation can not only protect its members —such as Ukraine— but also redefine its place in the international system.
In a world where old alliances are being tested, and new threats are emerging, the Commonwealth has a unique opportunity to lead.
The time has come to move beyond tradition and embrace a future where collective defence is central to preserving peace and stability.
The question is no longer whether the Commonwealth should change — but whether it can afford not to.
Vichana Sar is a researcher based at the Royal Academy of Cambodia. He holds Master’s Degree in Public Management MPM from South Korea’s KDI School of Public Policy and Management and a Master’s of Education from the Royal University of Phnom Penh. The views and opinions expressed are his own.
