The Supreme Court of the United States has held that foreign nations are entitled to sue for treble damages under section 4 of the Clayton Act.
Pfizer, Inc. v. Government of India, 434 U.S. 308 (1978).
Helen L. Collins,
Antitrust Law - Sherman Act - Sections 1 and 2 - Clayton Act - Section 4 - Interpretation of the Term "Person",
Duq. L. Rev.
Available at: https://dsc.duq.edu/dlr/vol17/iss2/14