The efficiency of geminate recombination after bimolecular ionization of an excited electron donor (or acceptor) is studied. For ions starting from inside or outside the recombination layer, the recombination efficiency has the opposite viscosity dependence. As a result the latter becomes nonmonotonous, provided the kinetic controlled ionization gives way to a diffusional one, creating the more remote ions the higher the solvent viscosity. This effect, first discovered experimentally, receives its explanation here, which is conceivable only on the basis of the Integral Encounter Theory of remote electron transfer in the liquid state.