  R{\'e}union is a European island in the heart of the Indian Ocean, far from
the resources of mainland France. It's an island rich in diversity, and faces a
number of societal challenges. Many players are working together to support the
transformation of its societal model towards one based on territorial and
collective resilience. In this article, we propose to look back at the studies
and experiments carried out over the last few years in La R{\'e}union by a
research group working in the field of multi-agent simulation, and to use
examples to show how this approach can contribute in a very concrete way to the
processes of understanding and manufacturing behavioral and spatial planning
models for a territory. We begin by outlining the basic principles of the
multi-agent approach, then present our feedback from experiments in various
fields of territorial foresight. The article concludes with a presentation of
the research team's approach to forging links between stakeholders involved in
territorial transformation, through the facilitation of a think-tank.
