Cassirer v. Thyssen-Bornemisza Collection Foundation

Summary

The Court held that in an FSIA action raising non‑federal claims, the substantive law is determined by the choice‑of‑law rule of the forum State—the same rule that would apply in a comparable suit against a private party. The decision vacated the Ninth Circuit’s judgment, which had applied a federal common‑law choice‑of‑law rule, and remanded for further proceedings applying California’s choice‑of‑law rule.