This article describes how an international group of infant-family researchers, practitioners, program directors, and advocates have helped the World Health Organization recognize the importance of caregiving relationships to children's survival, health, and development. When children lack contact and attachment to caregivers, they may fail to thrive, even when good medical and nutritional care is provided. The World Health Organization's evolving strategy for supporting children's "surviving and thriving" emphasizes the importance of caregiver-child interactions. An international group of colleagues works with nonprofessionals to strengthen caregiver-child relationships, even in emergency conditions such as war, extreme poverty, and the AIDS epidemic.