Small Island Developing States (SIDS) have long pursued unconventional economic development strategies, often with great success. Equally, because of their susceptibility to exogenous shocks, which can be disproportionately more destructive than in larger states, their progress remains fragile and can be set back suddenly and dramatically. It has taken some time for donors and multilateral institutions to recognise this, but climate change has brought the unique condition of SIDS to the fore and their ‘special case for sustainable development’ is now enshrined in the Small Island Developing States Accelerated Modalities of Action (‘SAMOA Pathway’) and other multilateral agreements. The problem is that, amid a rapidly changing geopolitical and economic landscape defined by the Covid-19 pandemic, the reassertion of great power politics and accelerating climate change, it is less clear what ‘sustainable development’ means for SIDS and what the best route to achieving it is.