Two cases studies are presented for the purpose of providing material for theoretical discussion on the development of adolescents in the nuclear age. The two cases originate from a study of 15 girls who were followed from the age of 15-16 to 17-18. Both cases showed an initial concern about nuclear war in earlier adolescence, but their subsequent development proceeded in opposite directions. The first case demonstrates how privatization and turning away from global issues might develop in one's mind and way of life. The second case demonstrates widening interests and activities in the global domain. The cases are analysed using the Vygotskian concepts of internalization and the zone of proximal development. It is suggested that the development of mass media has created a new zone of proximal development in adolescence, the global domain. It is suggested further that an integrated world view is a developmental potential inherent in the global domain.