  Weakly disordered two-dimensional superconductors undergo a
Kosterlitz-Thouless (KT) transition, where at a critical temperature vortices
proliferate through the system and destroy the superconducting (SC) order. On
the other hand, it was suggested that for large disorder the systems separates
into regions of high SC order, and it is the percolation of coherence between
these regions that is lost at the critical temperature. Here we demonstrate
that these two descriptions are just the dual of each other. A vortex causes
loss of local correlations, and thus the loss of percolation of correlations is
concomitant with percolation of vortices on the dual lattice, in the
perpendicular direction, i.e. the KT transition.
