This article serves as the introduction for this special issue of Global Governance on international migration. It presents some of the key facts, figures, concepts, and debates on international migration that appear in the articles that follow, and outlines their main arguments. Five arguments in support of greater international cooperation and more formal processes of global governance on international migration are presented here. First, contemporary international migration is now occurring at unprecedented levels and has a truly global reach. Second, international migration can no longer effectively be managed or controlled by national migration policies, and greater international cooperation is required to achieve national goals in international migration. Third, there are growing numbers of migrants around the world who are vulnerable…