There are numerous publications on the interpretation of Article 30 of the EC Treaty by the European Court of Justice1 which for the last 20 years has been one of the most controversial issues in EC law. It is, however, surprising that there is much older, yet strikingly similar, case law of the US Supreme Court which has remained almost unnoticed in Europe. In this article the respective case law of the two courts will be compared. Such a comparison is not only of interest as such, but can also contribute to the discussion about the correct scope of Article 30—which has certainly not yet been exhausted.