This article examines the ideas of Mexican elites about the international market during the porfiriato (1876–1910), an age marked by imperialism and monopoly capitalism. It focuses specifically on their thoughts about foreign trade, investment and workers. They viewed the international economy as a Darwinian battle for survival, but were not isolationists. In keeping with opinions articulated by US imperialists, they maintained that foreign blood, money and goods were essential to Mexico's economic progress. But they also feared that foreign economic penetration would undermine sovereignty. To resolve this dilemma, they championed state regulation of foreign economic interests. Thus, rather than extol the virtues of laissez-faire, members of the Porfirian intelligentsia were ambivalent internationalists.