1. An apparatus for modeling a physical network, comprising: a processor operable to execute preprogrammed instructions; and a memory operable to store computer programmed instructions executable by the processor for performing the steps of: constructing a model including a plurality of terminating vertices representing system nodes, a plurality of edges interconnecting the plurality of vertices representing transmission paths between the network nodes, and a non-terminating vertex on at least one of the plurality of edges representing a non-nodal vulnerability of the network; and performing a vulnerability analysis utilizing the constructed model.