This paper offers a solution to 'The Problem of Sustainable Economic Development' on islands. This hypothesis offers a foundational, sub-game solution to The Island Survival Game, a counterintuitive, dominant economic development strategy for ‘islands’ (and relatively insular states). This discourse also tables conceptual building blocks, prerequisite analytical tools, and a guiding principle for The Earth Island Survival Game, a bounded delay supergame which models 'The Problem of Sustainable Economic Development' at the global level. We begin our exploration with an introduction to The Principle of Relative Insularity, a postulate which informs ESS for ‘island’ and ‘continental’ players alike. Next, we model ‘island’ economic development with two bio-geo-politico-economic models and respective strategies: The Mustique Co. Development Plan, and The Prince Edward Island Federal-Provincial Program for Social and Economic Advancement. These diametrically opposed strategies offer an extraordinary comparative study. One island serves as a highly descriptive model for 'The Problem of Sustainable Economic Development'; the other model informs ESS. 'The Earth Island Survival Game' serves as a remarkable learning tool, offering lessons which promote islander survival, resource holding power, cooperative behaviour, and independence by illuminating the illusive path toward sustainable economic development.