The high density of scattered partons predicted in nuclear collisions at very
high energy makes color screening effects significant. We explain how these
screening mechanisms may suppress nonperturbative, soft QCD processes,
permitting a consistent calculation of quark-gluon plasma formation within the
framework of perturbative QCD. We present results of a model calculation of
these effects including predictions for the initial thermalized state for heavy
nuclei colliding at RHIC and LHC.