In the case of United States v. Sisson in 1969, the U.S Supreme Court ruled in favor of David J. Sisson who had been convicted for refusing induction into military service during the Vietnam War on grounds that it was an "unjust" and "immoral" war. The court held that a conscientious objector could be exempted from military service if his objections were based on moral or ethical beliefs about what is right and wrong, which are sincerely held with the strength of traditional religious convictions. This ruling expanded upon previous interpretations of draft law exemptions by including non-religious moral or ethical beliefs as valid reasons for objection to military service.

In the dissenting opinion for United States v. Sisson, Justice Hugo Black disagreed with the majority's interpretation of a provision in the Universal Military Training and Service Act that allowed conscientious objectors to refuse military service. He argued that this provision was meant to apply only to those who objected on religious grounds, not political or moral ones as was the case with Sisson. Furthermore, he contended that even if it did apply more broadly, Sisson had failed to demonstrate a consistent pattern of pacifist beliefs necessary for such an exemption. Justice Black also criticized his colleagues' decision as judicial overreach; they were interpreting laws rather than simply applying them which is outside their purview according to him.