In the case of Kolovrat et al. v. Oregon in 1960, the U.S Supreme Court ruled that an Oregon law prohibiting non-resident aliens from inheriting property was unconstitutional and violated treaty obligations with Yugoslavia. The plaintiffs were Yugoslavian nationals who had inherited land in Oregon but were denied ownership due to their alien status under a state statute. They argued this was discriminatory and conflicted with a bilateral treaty between the United States and Yugoslavia which allowed citizens of each country to inherit personal property situated within the other's territory on equal terms as native citizens would be able to do so. The court agreed, finding that while states have broad power over inheritance laws, they cannot infringe upon federal treaties or discriminate against foreign nationals without justification. It held that there was no valid reason for discriminating against these particular individuals based solely on their nationality or residence outside of America; thus, it struck down the law as unconstitutional.

In the dissenting opinion for Kolovrat et al. v. Oregon, Justice Frankfurter argued that the majority's decision was a departure from established principles of international law and comity among nations. He contended that it was not within the purview of individual states to determine whether they would recognize rights based on foreign laws or treaties; rather, this power resided with the federal government alone. Furthermore, he disagreed with the majority's interpretation of Oregon state law as barring enforcement of inheritance claims originating under Yugoslav law due to its socialist nature. Instead, he believed such an interpretation should be avoided unless explicitly stated by legislation or judicial precedent in order to maintain good relations between nations and uphold individuals' property rights regardless of their nationality or domicile.