Arnold & Porter Wins Major Victory for the Republic of Korea in US$4.7 billion Lone Star Dispute

Arnold & Porter has secured a landmark victory for the Republic of Korea in the Lone Star v. Korea International Centre for Settlement of Investment Disputes (ICSID) arbitration. On November 18, 2025, a three-member panel appointed by ICSID (“Committee”) annulled the part of the arbitral tribunal’s final award that had held Korea liable for a breach of its investment treaty obligations. The Committee found that the tribunal’s finding of liability was tainted by a due process violation and could not stand. The decision eliminates Korea’s liability under the award, while at the same time affirming the parts of the award that had dismissed other claims by the investors, and awarding Korea its full legal costs of the annulment proceeding.

Arnold & Porter partner Anton Ware, who acted as lead counsel for Korea in the annulment proceeding, commented: “The Committee’s decision is a resounding success for Korea and a vindication of the principle of due process in international arbitration.” Arnold & Porter partner Paolo Di Rosa, who, together with Anton, led the defense of Korea throughout the Lone Star arbitration, added: “The Committee’s decision stands as a testament to the ability of the ICSID system, through its annulment mechanism, to correct injustice in the arbitral process.” Another key member of the defense team, Arnold & Porter partner Jun Hee Kim, who leads the firm’s Korea practice, added: “This is an important victory for Korea, and we are honored to have represented the Government in this case.”

Arnold & Porter represented Korea throughout the 10-year duration of the underlying proceedings. In 2022, an arbitral tribunal ruled dismissed almost all of the investors’ claims against Korea. However, a majority of the tribunal held Korea liable on one claim and awarded damages of more than US$216 million plus interest (less than 5% of the more than US$4.67 billion in damages that Lone Star had sought). The Committee’s decision annuls in its entirety the tribunal majority’s finding of liability and the damages award.

The Arnold & Porter team was led by partners Paolo Di Rosa, Jun Hee Kim, and Anton A. Ware, and included senior associates John Muse-Fisher, Katelyn A. Horne, and Brian Bombassaro.