In the case of United States v. Concentrated Phosphate Export Association, Inc., et al., 1968, the U.S Supreme Court ruled that an association of American phosphate producers who controlled a significant portion of global exports were in violation of antitrust laws. The defendants argued that their activities fell under the protection of the Webb-Pomerene Act which allows for certain cooperative exporting arrangements. However, it was found that they had engaged in practices such as price-fixing and market allocation which went beyond what is permissible under this act. Furthermore, these actions had a substantial impact on domestic commerce by restricting competition and inflating prices within America itself - something not covered by any exemption provided by Webb-Pomerene Act. Therefore, despite their argument to be exempt from antitrust scrutiny due to international trade considerations, the court held them accountable for violating Sherman Antitrust Act.

In the dissenting opinion for United States v. Concentrated Phosphate Export Assn., Inc., Justice Fortas argued that the majority's decision to apply antitrust laws to export associations was misguided and could potentially harm American businesses operating in foreign markets. He contended that Congress, through the Webb-Pomerene Act, intended to exempt such associations from antitrust scrutiny as long as they did not engage in anti-competitive behavior within domestic markets. According to him, this exemption was designed specifically so U.S companies could compete effectively with foreign firms often backed by their governments or shielded by national trade policies. The majority’s interpretation of the law would undermine these intentions and put American exporters at a disadvantage on international stage. Furthermore, he disagreed with how broadly the court defined "restraint of trade," arguing it should only be applied when there is an actual adverse effect on competition rather than merely potential one.