We are in the first years of the United Nations Decade of Ocean Science for Sustainable Development 2021–2030 (the ‘Ocean Decade’). The Decade is intended to stimulate science and knowledge generation “for the ocean we want”, but does not consider how the ocean can contribute to mitigating conflict and building peace. This is a missed opportunity according to a new review paper published in Current Opinion in Environmental Sustainability. The paper is written together with Centre colleagues: Jean-Baptiste Jouffray, Albert Norström, Cibele Queiroz and Henrik Österblom, as well as Colette Wabnitz from Stanford University. By “tapping into the environmental peacebuilding literature” the six researchers come to the conclusion that the Ocean Decade has a considerable untapped potential to become an instrument of peace.