Spiro opposed the Vietnam War as not conforming to the Catholic theory of just war. As the conscription laws in the United States allowed for conscientious objection only on the grounds of opposition to all war, Spiro was labeled a "selective conscientious objector" and was convicted of avoiding the draft.United States v. Spiro, 384 F.2d 159 (3d Cir. 1967)Hugh C. Macgill, Selective Conscientious Objection: Divine Will and Legislative Grace, Virginia Law Review 1355 (1968). His case was championed by the newly formed Catholic Peace Fellowship; Daniel Berrigan, Tom Cornell, and Thomas Merton all lobbied on his behalf. The sincerity of his beliefs were recognized, as he received a five-year suspended sentence for his actions, and he was later pardoned by President Gerald Ford. He was "more proud of the conviction than the pardon" and throughout his life he referred to himself as a "political criminal."
