In the Cramer v. United States case of 1944, Anthony Cramer, a German-born naturalized American citizen was convicted for treason against the U.S. during World War II due to his association with two German spies who had landed in America via submarine. The Supreme Court overturned his conviction by a vote of five to four on grounds that while he did have associations with these individuals, there wasn't sufficient evidence proving that he provided them aid and comfort - an essential element required for conviction under Article III Section 3 of the Constitution which defines treason as giving "aid and comfort" to enemies. This ruling established stricter standards for what constitutes treasonous behavior; mere association or sympathy towards enemies is not enough unless it involves overt acts aiding such enemies.

In the dissenting opinion for Cramer v. United States, Justice Robert H. Jackson disagreed with the majority's interpretation of treason as defined by the U.S. Constitution and argued that it was too narrow in scope. He contended that Anthony Cramer had indeed committed an act of treason by providing aid to German spies during World War II, even if he did not directly participate in their espionage activities or share their objectives. According to Justice Jackson, any form of assistance given to enemies during wartime should be considered a traitorous act because it undermines national security and aids enemy operations against the country regardless of intent or direct involvement in hostile actions.