Deprived of identity, Giacometti's L'Homme qui marche reminds us that humanity has known cross-border migration for millennia. This very ordinary social fact constitutes, however, an object for criminal law, which can act with regard to irregular migration and migration for terrorist reasons. But from this confrontation, the criminal law emerges tested. It is first of all instrumentalized in the face of irregular migration, its action being intended only to facilitate the implementation of administrative expulsion measures or to prevent irregular border crossings. Criminal law is then overtaken in the face of migration for terrorist reasons, this by the rise of administrative police measures - such as the ban on leaving the territory which, by anticipating to the extreme the terrorist risk carried by the migration, lead to the obsolescence of criminal law and in particular of its guarantees.