  We point out that there is a natural explanation, in terms of the center
vortex confinement mechanism, for the expected Casimir/Sine Law scaling of
k-string tensions in the large N limit. The crucial ingredient is the existence
of Z(N) center monopoles, which go over to U(1) monopoles in this limit. Vortex
densities leading to Casimir/Sine Law scaling at large-N are constructed; these
densities have no obvious pathologies and in particular do not grow with N. We
also note that center vortices are stable classical solutions of the Wilson
action, for all SU(N) gauge theories with N>4, and extend this old result to a
broad class of lattice actions motivated by the improved action program and the
renormalization group.
