 When the antitrust laws were reinstated after about 1937, Stocking served through the early 1940s as an economic adviser to the great head of the Antitrust Division of the Department of Justice, Thurman Arnold.It was Arnold who initiated for the first time a large number of successful U.S. criminal prosecutions of international cartels in the mid-1940s.Information from these prosecutions and from Congressional investigations of the nefarious roles played by cartels in facilitating the economic policies of national socialism formed the basis of Stocking's two landmark books on international price-fixing cartels.