Nature Sustainability, Published online: 28 July 2026; doi:10.1038/s41893-026-01874-z Indigenous Lands are critical for protecting Indigenous Peoples and the Amazon. Yet, they are increasingly exposed to socio-environmental frontiers, bringing violence, illegal resource extraction and deforestation. Urgent action is required to prevent irreversible harm to both people and forests, particularly in Brazil’s Vale do Javari Indigenous Land.