On 12 July 2016, the Permanent Court of Arbitration in The Hague issued one of the most consequential rulings in contemporary maritime law. The tribunal unanimously concluded that China’s expansive claims in the South China Sea, particularly those based on so-called “historic rights”, lacked legal foundation under the United Nations Convention on the Law of the Sea (UNCLOS). Ten years later, however, the significance of that decision lies less in its legal conclusions than in a more fundamental question: can international law still shape state behaviour when confronted by geopolitical realities?
The joint statement issued this month by fifteen countries—including Japan, Australia, Canada, Germany, Italy, Latvia, Lithuania, New Zealand, the Philippines, Romania, Slovenia, the United Kingdom and the United States—is therefore about far more than commemorating an anniversary. It represents a collective reaffirmation that legal norms remain an indispensable foundation of international order, even when their enforcement proves difficult. At a time when strategic competition increasingly challenges established rules, defending the authority of international law has itself become a strategic objective.
The South China Sea encapsulates one of the defining contradictions of the twenty-first century. Economic interdependence has deepened while geopolitical rivalry has intensified. Few regions illustrate this tension more clearly. A substantial proportion of global maritime trade passes through these waters, making freedom of navigation not simply a security concern but an essential condition for international commerce. For governments, investors and businesses alike, legal predictability at sea is not an abstract principle; it is a prerequisite for economic stability and sustained prosperity.
The 2016 arbitral award did not resolve the dispute, nor could it reasonably have been expected to do so. International tribunals rarely possess the means to enforce their decisions directly. Their authority derives instead from legitimacy. Judicial rulings establish legal reference points that shape diplomatic positions, influence state practice and distinguish internationally recognised norms from assertions based primarily on political or military power. In this respect, the lasting significance of the South China Sea award extends far beyond the dispute itself.
This explains why the recent joint statement deserves careful attention. Its purpose is unlikely to be persuading Beijing to alter its position overnight. Rather, it seeks to reaffirm a more fundamental principle: that international disputes should continue to be governed by commonly accepted legal rules rather than by relative power alone. This distinction is neither merely legal nor exclusively political. It has direct consequences for international trade, investment and long-term economic confidence. Markets flourish where legal certainty prevails. They become considerably more fragile when strategic ambiguity replaces predictable rules.
Ten years after the arbitral award, the central question is no longer whether the tribunal correctly interpreted international law. The more enduring issue is whether the international community remains willing to defend the principle that international law continues to constitute a legitimate constraint on the exercise of power. The answer will shape not only the future of the South China Sea, but also the credibility of the rules-based international order upon which much of global stability and prosperity ultimately depends.
