In the case of Service v. Dulles, John S. Service, a former U.S. Foreign Service Officer was dismissed from his position by Secretary of State John Foster Dulles under Section 401 (h) of the Career Diplomatic Personnel Act for alleged disloyalty to the United States during World War II and in China after WWII ended. The Supreme Court ruled that this dismissal was unlawful as it violated due process rights because he had already been cleared twice by Loyalty Security Board hearings which found no reasonable doubt about his loyalty to America. Furthermore, they held that Section 401(h) could not be used retroactively against actions committed before its enactment in 1947; thus any allegations prior to this date were irrelevant for dismissal purposes under this section.

In the dissenting opinion for Service v. Dulles, Justice Felix Frankfurter argued that the court had overstepped its bounds by intervening in a matter of foreign policy and national security. He contended that it was not within the purview of the judiciary to question or interfere with decisions made by executive departments regarding personnel matters, particularly when those decisions were based on considerations of national security. Furthermore, he asserted that Congress had explicitly given Secretary Dulles authority to dismiss employees who posed potential risks to national security and therefore his decision should be respected. In essence, Justice Frankfurter believed that this case represented an inappropriate intrusion into executive discretion and undermined principles of separation of powers.