A 60-Year Grievance: Exxon Takes on Sovereign Immunity; Exxon Mobil Corp. v. Corporación Cimex

On October 3, 2025, the Supreme Court granted certiorari in a case that was thought to be a relic of the Cold War. Exxon Mobil Corp. v. Corporación Cimex, S.A. traces back to when Fidel Castro and the Cuban government nationalized U.S oil refineries in 1960 without compensation. Until 2019, there was no legal avenue for Exxon to reclaim its Cuban subsidiaries. The guiding principle for private foreign disputes was the Foreign Sovereign Immunities Act (FSIA) of 1976, which grants foreign states immunity from lawsuits in U.S. courts unless an exception applies. While Title III of the Cuban Liberty and Democratic Solidarity Act (Helms–Burton Act) in 1996 enabled U.S. nationals whose property was confiscated by Cuba to sue “any person” engaged in that seizure, every subsequent president suspended this clause in fear of stirring diplomatic chaos. President Trump, however, activated Title III for the first time in April 2019, leading to Exxon’s swift lawsuit a month later. This case presents the question of “[w]hether the Helms-Burton Act abrogates foreign sovereign immunity in cases against Cuban instrumentalities, or whether parties proceeding under that act must also satisfy an exception under the Foreign Sovereign Immunities Act.” The SCOTUS ruling will determine whether private litigants can act as proxy enforcers of U.S. sanctions, a pertinent topic to the Russian-Ukrainian War and Chinese tariffs. With these ongoing geopolitical tensions, the Court risks turning federal courts into geopolitical battlegrounds if it rules in favor of Exxon, letting them receive compensation at the expense of sovereign immunity.

In the past five years, district and circuit courts have debated whether the Helms–Burton Act overrides the FSIA, and whether Exxon fulfills the exceptions in the FSIA, ultimately sending the fate of this case to SCOTUS. The lawsuit Exxon filed was against three Cuban state-owned entities, Corporación CIMEX, S.A. (Cuba), Corporación CIMEX, S.A. (Panama), and Unión Cuba-Petróleo, for trafficking three oil refineries and related facilities worth over $700 million today. According to 22 U.S.C. § 6023(11), the word “person” is defined as “including any agency or instrumentality of a foreign state.” Such a definition, as mentioned in Helms–Burton Title III, should apply to Exxon, but the lower courts ruled differently. Both the D.C district and Circuit courts deemed that Title III doesn’t automatically override FSIA’s immunity rules. Among the two relevant exceptions in the FSIA, expropriation (for property taken in violation of international law) and commercial activity (if the foreign state’s commercial actions have a direct effect in the U.S.), Exxon’s claim remains ambiguous. The district court rejected the expropriation exception because international law generally doesn’t forbid a country from expropriating its own national property. Exxon was merely the parent company of locally incorporated subsidiaries, built on Cuban soil and registered under Cuban law. As for the commercial activity exception, the D.C. Circuit remanded the case in July 2024 for further fact-finding to determine whether the exception applies. At the same time, they decided against Exxon on the basis that Helms–Burton does not abrogate sovereign immunity. Still persistent, Exxon filed a petition for writ of certiorari to SCOTUS in December 2024. Nevertheless, building a case around Title III leaves many vulnerabilities.

The Court has previously ruled in cases where FSIA was abrogated by a clear congressional mandate, but it isn’t clear that the Helms–Burton Act fits into that category. For instance, in 2004, the Court applied the FSIA expropriation exception in Republic of Austria v. Altmann. This case involved six paintings from the Austrian Gallery, which Maria Altmann’s uncle owned and were seized by Austria after World War II or by the Nazis. The question of this case was whether FSIA can be applied retroactively, and the language in the statute clearly suggests that Congress intended it so, because judges interpreted the word “henceforth” to be non time-constraining. Hence, FSIA should be given priority over the Helms-Burton Act, unless exceptions apply. Furthermore, in another case more similar to Exxon’s, the clarity of the congressional mandate determines whether or not FSIA gets abrogated. In Rubin v. Islamic Republic of Iran (2018), U.S victims of terrorism requested Persian museum artifacts as collateral for their damage. However, because the Terrorism Risk Insurance Act did not explicitly mention cultural property, the FSIA was not abrogated, and Iran received immunity. In contrast, a clear example of abrogation is the Justice Against Sponsors of Terrorism Act of 2016, explicitly stating that immunity “shall not apply” to foreign states for supporting terrorism within the U.S. The Helms-Burton Act lacks this kind of decisive language to override FSIA, so Exxon will have to rely solely on fulfilling the Commercial Activity exception.

While the Helms-Burton Act is limited to Cuba, placing it above FSIA can seriously undermine the principle of comity: that courts should avoid judging foreign sovereign conduct unless Congress clearly directs them to do so. Comity is integral to the separation of powers, as foreign relations are primarily the domain of the political branches, not the judiciary. If the Court allows Exxon to proceed with litigation under Title III, then any private firm can use any vague piece of legislation to litigate any foreign entity. Whatever the outcome, as long as Exxon maneuvers through the FSIA exception, and not the Title III approach, FSIA will still hold authority in the court system. The Court’s final decision will determine the survival of sovereign immunity in a globalized economy.