## Facts

- Current and former residents of Bougainville Island, Papua New Guinea (PNG), sued Rio Tinto plc and Rio Tinto Limited for harms allegedly arising from operation of the Panguna copper mine.
- Plaintiffs alleged the mine discharged large quantities of tailings and waste, severely polluting rivers and coastal areas, damaging crops and fisheries, and causing long-term environmental and health harms.
- Plaintiffs alleged Rio Tinto engaged in racially discriminatory practices toward Bougainville residents and that mine-related conflict contributed to civil unrest and armed conflict on the island.
- Plaintiffs further alleged that during the conflict PNG forces imposed a blockade restricting medical supplies and humanitarian aid, causing deaths and serious suffering, and that Rio Tinto supported or was complicit in this conduct.
- Plaintiffs brought claims primarily under the Alien Tort Statute (ATS), asserting violations of customary international law, including war crimes/law-of-war violations, racial discrimination, and environmental/marine pollution norms (citing UNCLOS as relevant evidence).

## Issues

1. Whether the complaint alleged violations of sufficiently “specific, universal, and obligatory” norms of customary international law to support ATS jurisdiction, particularly for environmental/marine pollution claims.
2. Whether the act of state doctrine barred claims that would require adjudicating the validity or wrongfulness of official acts of the PNG government within its territory.
3. Whether the political question doctrine barred adjudication because the dispute implicated sensitive foreign-affairs considerations.
4. Whether principles of international comity and the availability of PNG fora supported dismissal.
5. Whether UNCLOS could supply, or meaningfully evidence, an ATS-cognizable norm applicable to the alleged pollution.

## Decision

- The court granted the motion to dismiss in substantial part.
- The court dismissed the ATS environmental claims for lack of subject-matter jurisdiction, finding no sufficiently definite and universally accepted customary international law norm governing the alleged environmental harms.
- The court held the act of state doctrine barred adjudication of the environmental and racial discrimination claims to the extent resolving them would require invalidating or passing judgment on PNG governmental acts.
- The court held the political question doctrine barred adjudication of all claims, relying in part on the U.S. State Department’s Statement of Interest warning of potential adverse foreign-relations effects.
- The court also treated international comity and the adequacy of PNG as an alternative forum as additional support for dismissal.

## Legal Principles

- ATS jurisdiction requires alleging a violation of a customary international law norm that is specific, universal, and obligatory; generalized references to international environmental protection are insufficient without a clearly defined norm.
- Treaties such as UNCLOS may be considered as evidence of international law, but do not automatically create a private cause of action or establish a sufficiently determinate customary norm for ATS jurisdiction.
- Under the act of state doctrine, U.S. courts generally will not adjudicate claims that require declaring invalid a foreign sovereign’s public acts performed within its own territory.
- The political question doctrine can bar transnational human-rights litigation when adjudication would intrude on foreign-relations functions committed to the political branches, especially where the executive branch indicates diplomatic sensitivity.
- International comity may support dismissal where the foreign state has a strong regulatory interest and provides an adequate forum for resolving the dispute.

## Conclusion

The court dismissed the Bougainville ATS action largely on threshold grounds, holding that the pleaded environmental harms did not rest on a sufficiently definite customary international law norm and that the act of state and political question doctrines, reinforced by comity concerns and executive-branch foreign-relations views, made the dispute nonjusticiable in U.S. court.


Sarei v. Rio Tinto PLC, 221 F. Supp. 2d 1116 (C.D. Cal. 2002)