  The IceCube collaboration has recently identified events due to
ultrahigh-energy neutrino interactions. Predictions of the neutrino-nucleon
cross section at ultrahigh energies require a huge extrapolation of the cross
sections experimentally measured at laboratory energies. Upon relating neutrino
scattering to deep inelastic electron scattering, we show that the empirically
verified color dipole picture is well suited for such an extrapolation. The
dominant contribution to the total neutrino-nucleon cross section, even at
ultrahigh energies, is due to the kinematic range where color transparency is
valid for the color dipole interaction. We deviate from various claims in the
literature on the presence of screening effects due to non-linear evolution at
ultrahigh neutrino energies.
