The concept of sustainability has taken centre stage in Arctic politics. However, there is little agreement on what ‘sustainable’ means. For different actors (governments, indigenous people, NGOs, etc.) the concept implies different sets of opportunities and precautions. Sustainability, therefore, is much more a fundamental idea to be further elaborated depending on contexts than a definable term with a specific meaning. The paper argues a research agenda that aims to map and analyse the role of sustainability in political and economic strategies in the Arctic. Sustainability has become a fundamental concept that orders the relationship between the environment (nature) and development (economy), however, in the process rearticulating other concepts such as identity (society) and security (state). Hence, we discuss, first, how sustainability when meeting the Arctic changes its meaning and application from the global ecosphere to a regional environment, and, second, how sustainability is again conceptually transformed when meeting Greenlandic ambitions for postcoloniality. This discussion leads us to outline an agenda for how to study the way in which sustainability works as a political concept.