Popularity Has Never Been a Legal Test
When volume of opinion is confused with legal obligation, the authority of law itself begins to erode.
International law is increasingly framed through the language of consensus. Open letters accumulate signatures. Petitions gather momentum. Collective declarations are presented as if they carry inherent legal weight. The implicit argument is seductive: if enough voices say something, it must have legal force.
It doesn't work that way. It never has.
Courts do not decide cases by counting signatures. Legal obligations do not materialise because a position enjoys widespread support. And yet the elevation of consensus to a quasi-legal threshold is becoming one of the most corrosive trends in contemporary legal discourse.
The Foundations That Actually Matter
International law operates through deliberately narrow sources. Treaties create binding obligations between parties. Customary practice, when accompanied by opinio juris (a state's sense of legal obligation), generates binding norms. General principles of law and judicial decisions provide additional authority.
These mechanisms exist to prevent law from becoming a mirror of public sentiment. As Michael Schmitt and Sean Watts have observed, "State opinio juris remains the critical bellwether for the degree of consensus, acceptance, and therefore effectiveness and legitimacy of any international legal rule."
What matters is not how many voices speak, but whether states understand themselves to be bound by a legal obligation. That distinction is foundational.
The US government made this point in its response to the ICRC study on customary humanitarian law, noting the study frequently fails to demonstrate rigorous state practice and opinio juris necessary to establish customary law.
Consensus might inform debate. It does not substitute for jurisdiction, evidence, or legal reasoning.
Where the Confusion Creates Danger
Treating consensus as if it were a legal standard generates several predictable risks.
Courts under pressure
When widespread agreement is presented as legally determinative, courts face mounting pressure to appear responsive rather than rigorous. The implicit accusation becomes: if you don't align with consensus, you're obstructing justice.
This erodes judicial independence. Legal authority weakens not because it is contested, but because it is mischaracterised. Judges apply law, not validate sentiment.
Disagreement recast as illegitimacy
When consensus is treated as a threshold for legality, dissent stops being an ordinary feature of legal dispute. Instead, it becomes framed as obstruction or bad faith.
Yet dissent is essential to legal development. Many of the most durable legal principles emerged in contexts of profound disagreement, clarified through method rather than acclamation.
Justice Scalia noted that redefining the "law of nations" to mean "the consensus of states on any subject" is "a 20th-century invention of internationalist law professors and human rights advocates" inconsistent with constitutional principles.
Non-state actors displacing state authority
The elevation of consensus also risks displacing states in international lawmaking. As a recent analysis observed, non-state actors have moved into the "declaratory" space whilst states have become reticent about articulating legal views.
Scholars, NGOs, and advocacy organisations contribute valuable perspectives. But their views cannot substitute for state opinio juris. When non-state commentary is treated as customary law, the state-centric process is undermined.
The Real Issue Nobody's Discussing
The danger here isn't that people care about international law. Public engagement is vital. Broad concern can highlight issues worthy of serious scrutiny.
The danger is that consensus is being treated as a shortcut around the discipline law requires.
As noted in relation to UN resolutions, "these resolutions or declarations are only recommendations" regardless of consensus. Agreement does not create obligation unless formal sources of law are satisfied.
What's at Stake
If international law is to retain credibility, it must resist conflating popularity with validity. Consensus may be persuasive in politics, but law demands something more exacting.
Its strength lies not in how many voices repeat a claim, but in whether that claim survives the standards the law itself has established. When we lose sight of that distinction, we make law arbitrary rather than responsive, turning legal institutions into arbiters of sentiment rather than guardians of rules.