Root served as United States Secretary of State and promoted the idea that law should prevail over force in diplomacy. From 1904 onward he concluded several arbitration treaties in which nations agreed in advance to submit disputes to an impartial tribunal. In 1906 he toured Central and South America, delivering speeches that strengthened mutual understanding between North and South America and proposing an international judicial body at the Pan-American Conference. These initiatives brought institutionalized peaceful methods into international society on the eve of World War I. The framework he outlined later evolved into the Permanent Court of International Justice and eventually the International Court of Justice of the United Nations. His work was praised because it translated pacifist ideals into concrete laws and treaties. Today, when we hear about international arbitration or the world court, we witness the continuation of the path he helped open. Root’s Nobel Prize therefore marks a pivotal moment in the history of institutional pacifism.

Elihu Root, as Secretary of State under Theodore Roosevelt, handled the 1905 U.S.–Mexico boundary dispute and the Dominican Republic debt issue through arbitration, successfully avoiding military intervention. He focused early on the machinery of the Permanent Court of Arbitration created by the Hague Peace Conferences and negotiated general arbitration treaties with more than thirty states, committing the parties to submit all but the most vital disputes to third-party judgment. The international court project he drafted in 1908, supported by President William Howard Taft and British Foreign Secretary Edward Grey, gave renewed momentum to plans for a multilateral judicial body. In that plan he envisioned a standing bench of international law experts working in tandem with an executive council comparable to today’s UN Security Council. Root also encouraged the building of inter-American telecommunication cables and a regional banking network, hoping that economic interdependence would deter war. His theoretical background drew on the doctrine of reciprocal citizenship and on John Bassett Moore’s jurisprudence, earning him respect as both politician and jurist. He founded the American Society of International Law, providing a platform linking academic scholarship with diplomatic practice. The spread of international arbitration influenced later institutions such as ICSID and UNCITRAL, extending peaceful settlement mechanisms to investment and trade disputes. Therefore, Root’s Nobel Prize is not an isolated event but a significant milestone in the long-term evolution of the international judicial system. His achievements remain frequently cited in contemporary international relations as an empirical demonstration of the compatibility of state sovereignty with an overarching legal order.

Root’s model arbitration treaties were innovative because they contained both advance consent clauses and detailed procedural selection provisions, in sharp contrast to traditional ad hoc conciliation. The 1908–1911 U.S.–UK and U.S.–France treaties, in particular, extended compulsory arbitration to questions of fact as well as of law, thereby furnishing the template for the draft Statute of the Permanent Court of International Justice. His blueprint for a permanent international court combined a standing roster of judges with the possibility of ad litem appointments by disputing states, reconciling regional representation with subject-matter expertise. To ensure compliance, he designed an enforcement system empowering an executive council to impose economic sanctions on states that ignored awards—an antecedent of the WTO’s retaliation mechanism. Root also emphasized cumulative jurisprudence through codification, establishing a feedback loop in which discussions in the American Society of International Law yearbooks crystallized into treaty drafts. Scholars regard his approach as a key inflection point in the transition from nineteenth-century natural law to twentieth-century positivist international law. The triadic design of broad arbitration clauses, expanded court jurisdiction, and binding enforcement mechanisms shaped inter-war judicial practice. Many of these institutional features survive in the contemporary ICJ framework, attesting to the enduring relevance of Root’s pioneering ideas.