Why is collective security the most effective deterrence?

Collective security is the process that runs parallel to disarmament. Its conceptual argument rests on the idea that collective defense is:

1. The most effective way to deter a potential aggressor.
2. The most cost-efficient scenario for military spending.
3. An architecture of mutual control and balance of power.
4. The collective security guarantee that would allow disarmament to advance.

Its current legal embodiment rests on Chapter VII of the United Nations Charter, which grants the Security Council primary responsibility for maintaining peace and the exclusive authority to authorize the use of force for that purpose.

The problem is that this collective security has proven ineffective due to the structural dysfunction of the Security Council: five members hold veto power and can block a collective security operation intended to stop an aggression in which one of them is involved (except in rare cases such as South Korea in 1950 or Kuwait in 1990).

“War will cease only when, and not until, it becomes evident beyond a shadow of doubt that in any war the aggressor will be defeated.” — Bertrand Russell, 1943.

“There is only one road to peace and security: the road of supranational organization.” — Albert Einstein, 1949.

The Second Charter proposes a reformed Security Council and a restricted veto power. In a reformed United Nations, the General Assembly (of 193 states) and a future Parliamentary Assembly (with proportional representation) could — through a concurrent vote — give effect to a Council resolution even if a member had vetoed it. In this way, the legal mechanism of collective security would, in theory, be unblocked.

Perhaps the most emblematic material example of collective security is the defensive alliance of the North Atlantic Treaty (NATO). Its main problem: it is not universal. It is a collective alliance of regional scope, based on the commitment that all members would defend any other in the event of an attack. This legal commitment (Article 5 of the Treaty) multiplies the defensive capacity of individual members.

But what about border states like Ukraine? Or isolated countries like Lebanon? Or distant regions like the Sahel or South Sudan? Could such aggressions be halted if a collective force existed in their regions? Or within the United Nations?

In our European context, one of the ongoing debates is whether the European Union should move toward its own collective security system (set out in its Treaties, Article 42 TEU) and give it form through a nascent European army. In any case, common European defense would be the most cost-efficient and effectively deterrent approach — far more so than the current trend of isolated, individual military spending by the 27 member states.

An International Peace Force: the lucid dream of our forebears

What would be the practical mechanism for putting international collective security into effect?

Our parents and grandparents laid the ideal foundations for believing that international peace and security were a feasible and necessary goal for the survival and progress of an interconnected humanity. In the lucid dream that was the creation of the United Nations and its Charter, they foresaw (Articles 43 to 47) the creation of an International Peace Force that, unfortunately, never materialized because of the distrust among powers. The outdated notion that a single hegemonic power could provide security and stability for the whole also played a role.

If collective security is the most effective form of deterrence, an International Peace Force may be the most suitable form of collective security. The closest experiences to an international force have been the UN peacekeeping missions (peacekeeping operations, the “Blue Helmets”). Over seven decades, these have yielded valuable operational and practical conclusions:

• The need for a permanent force, independent of national armies;
• The need for a single operational command, not one per participating state.
• The need for a stable budget and sufficient resources, not based on sporadic and voluntary national contributions;
• The need for the United Nations to have the capacity to acquire and procure state-of-the-art material, supplies, and weaponry.
• The need for training, a chain of command, and discipline of its own, in service of United Nations resolutions;
• The need for its own disciplinary and penal codes, with international (not national) jurisdiction, to which the officers of the international force would answer.

An International Peace Force, operating under the United Nations flag, could begin as a rapid-reaction division of around 10,000 troops. It would be recruited, trained, armed, and commanded by its own command structure, independent of national apparatuses. It would have its own bases, facilities, and equipment capacity, funded by the United Nations budget. It would fall under the jurisdiction and mandate of resolutions from a reformed Security Council, which would authorize its deployment, its disciplinary codes, and its rules of engagement in accordance with International Humanitarian Law. Such a force could also intervene (in support of national forces) in other human security emergencies, such as natural and environmental disasters or humanitarian crises.

However distant this proposal may seem, it is neither new nor impossible. Permanent national armies and regional alliances underwent comparable transformations that responded to the logic of effectiveness in deterrence and in the security of the whole. Can we work toward that goal in today’s context?

Building after the storm?

The world of 2026 is not the world of 1945. The 1945 Charter was pre-nuclear, pre-digital, and pre-climate change. Nor did it reflect today’s economic and demographic distribution (China, India, Brazil, the African continent). Moreover, it lacked the mechanisms, institutions, or means sufficient to address today’s and tomorrow’s needs and challenges.

Do we need to reimagine the United Nations and the architecture of international governance for a new generation? A World Parliament representing global citizens, a new way of organizing economic and trade dynamics between countries, new sources of funding for global public goods, a renewed disarmament process, or a Peace Force — these are some of the proposals that can guide this imaginative, creative, and collective effort. Sooner or later, humanity will have to revisit its institutions and rethink its structures. When that moment comes, the constructive efforts of the present will take on their full meaning.

The visions and proposals presented in this article come from the documents A Second UN Charter (2024) and Protocols Complementary (2025) published by the Global Governance Forum.