Filartiga v. Pena-Irala
In the 1984 appeal of Filartiga v. Pena-Irala, the U.S. Court of Appeals for the Second Circuit held "hold that deliberate torture perpetrated under color of official authority violates universally accepted norms of the international law of human rights, regardless of the nationality of the parties."  The case was based on the Alien Torts Claims Act.
Further, a commander could be held liable for tortures performed by subordinates, as in the doctrine of command responsibility. "The defendant in all but one of the cases was Gen. Carlos Guillermo Suárez Mason, whose clandestine presence in the U.S after fleeing prosecution in Argentina triggered lawsuits from several of his victims. As commander of the First Army Corps, Suárez Mason participated in the preparation of the 1976 coup, oversaw the operations of task forces, and was ultimately responsible for secret detention camps in the densely populated region comprising Buenos Aires and its suburbs, La Plata, Mar del Plata, and smaller cities."