Summary of Amicus Curiae Brief

This document is an amicus curiae brief filed by the Republic of Poland in the Supreme Court of the United States, in support of the Kingdom of Spain's petition for a writ of certiorari. The petition seeks review of a decision by the U.S. Court of Appeals for the District of Columbia Circuit concerning the enforcement of intra-European Union (EU) investment arbitration awards.

Key Arguments Presented

Poland argues that the D.C. Circuit's decision creates perverse litigation incentives and fosters harmful forum shopping. By permitting U.S. courts to confirm intra-EU arbitral awards—which are considered incompatible with EU law following the Court of Justice of the European Union's (CJEU) landmark decisions in *Achmea* and *Komstroy*—the ruling encourages investors to pursue wasteful and duplicative proceedings against EU Member States. Poland contends that this opens U.S. courts to enforcement actions that would be invalid within the EU's own legal order, thereby undermining international comity and subjecting sovereign states to burdensome litigation.

The brief challenges the D.C. Circuit's interpretation of the Foreign Sovereign Immunities Act (FSIA). Poland asserts that the appellate court erred in finding that the FSIA's arbitration exception, 28 U.S.C. § 1605(a)(6), was satisfied. The core of this argument is that a multilateral investment treaty, such as the Energy Charter Treaty (ECT), does not constitute a direct "agreement to arbitrate" between a state and a specific investor party to the dispute, as required by the statute's plain text. This interpretation, Poland argues, improperly expands the waiver of sovereign immunity beyond what the FSIA contemplates.

Furthermore, Poland criticizes the D.C. Circuit's establishment of a per se rule prohibiting district courts from considering the doctrine of *forum non conveniens* in proceedings to confirm foreign arbitral awards. This rule, the brief contends, not only creates a circuit split but is also inconsistent with Supreme Court precedent, which favors a flexible, fact-based application of the doctrine. Poland argues that this rigid prohibition forces litigation in a U.S. forum even when a foreign forum is manifestly more appropriate.

Relief Sought

The Republic of Poland respectfully urges the Supreme Court to grant the petition for a writ of certiorari to address these significant questions of federal jurisdiction, sovereign immunity, and international arbitration law, and to reverse the D.C. Circuit's decision.