  In this paper we will discuss how cosmic strings can be used to bridge the
gap between the local geometry of our spacetime model and the global topology.
The primary tool is the theory of foliations and surfaces, and together with
observational constraints we can isolate several possibilities for the topology
of the spatial section. This implies that the discovery of cosmic strings would
not just be significant for an understanding of structure formation in the
early universe, but also for the global properties of the spacetime model.
