Why do some international military interventions gain widespread support while others face greater scepticism? In answering this question, researchers have observed that international institutions like the UN Security Council and NATO play a key role in legitimising such interventions and thus garnering mass approval. Conventional wisdom suggests that factors like legality, material burden sharing, and regionalism determine whether an international institution can achieve this effect. A study by Assistant Professor
Jonathan Chu, Presidential Young Professor in International Affairs at the Lee Kuan Yew School of Public Policy at the National University of Singapore, theorises and demonstrates a novel explanation for why international institutions can confer legitimacy: by sending social cues.
Social cues — signals from individuals, leaders, and institutions representing a particular social community — play a decisive role in shaping public perceptions of foreign interventions. Even informed audiences, who might otherwise critically assess military actions, can be influenced by these cues. For example, when the North Atlantic Treaty Organization (NATO) — a recognised symbol of Democratic political identity — endorses military action, it can send a message that extends beyond legal or strategic justification; it taps into a shared sense of belonging and legitimacy within its community of democratic countries.
Published in
Cambridge University Press, Professor Chu’s research demonstrates that these cues create social pressure to conform, encouraging decision-makers to support interventions that align with their identity. This process can be particularly powerful in humanitarian interventions, where the moral and ethical stakes tend to be high. When a trusted, ingroup institution signals that an intervention is “right”, policymakers and the public are more likely to rally behind it.
The study reveals a key insight: legitimacy is not simply a matter of legality or strategic interest. Instead, it is deeply embedded in how institutions position themselves as part of a shared identity.
This finding challenges traditional notions of global governance. While many assume that international cooperation is driven by rational calculations — such as military burden-sharing or legal frameworks — Professor Chu’s research suggests that the social dynamics of legitimacy are just as, if not more, important. By leveraging their role as social influencers, institutions can shape public perception and drive collective action more effectively than previously understood.
In an era of rising nationalism, institutional distrust, and contested international interventions, understanding the role of social cues has never been more crucial. Policymakers and international organisations are tasked with rethinking how they communicate legitimacy — not just through legal or economic justifications, but by reinforcing the social and identity-based connections that make interventions politically viable.
As global governance faces increasing challenges, this research offers a timely perspective on how institutions can maintain credibility and influence in a rapidly evolving world.
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