The U.S. Supreme Court case Hellenic Lines Ltd. et al. v. Rhoditis in 1969 involved a dispute over the applicability of American law to an international maritime incident involving a Greek ship owned by a company with significant ties to the United States, and operated largely from there as well. The plaintiff was George Rhoditis, an alien seaman who had been injured while working aboard one of Hellenic Lines' ships and sought damages under the Jones Act, which provides protections for sailors injured at sea but is typically applied only within U.S jurisdiction or on American vessels. Hellenic Lines argued that since their vessel flew under a foreign flag (Greek), it should be exempt from such laws; however, because they maintained substantial business operations in America and were majority-owned by an American citizen (even though he held dual citizenship), the court ruled against them. In its decision, the Supreme Court expanded upon previous rulings regarding "substantial contacts" between businesses operating internationally and their connections to America - stating that these could extend beyond just ownership stakes or operational bases - thus allowing for broader application of domestic laws like those protecting workers' rights.

In the dissenting opinion for Hellenic Lines Ltd. v. Rhoditis, Justice Harlan disagreed with the majority's decision to extend American law jurisdiction over a foreign ship owned by a Greek corporation just because its principal shareholder resided in the United States. He argued that this interpretation of "American character" was too broad and could lead to unpredictable results in future cases involving international maritime disputes. Furthermore, he expressed concern about potential diplomatic implications if U.S courts were seen as interfering excessively in matters traditionally governed by foreign laws or international agreements. In his view, it would be more appropriate for such issues to be resolved through legislative action rather than judicial decisions.