  The classical Yang-Mills equations are solved perturbatively in covariant
gauge for a collision of two ultrarelativistic nuclei. The nuclei are taken as
ensembles of classical color charges on eikonal trajectories. The classical
gluon field is computed in coordinate space up to cubic order in the coupling
constant g. We construct the Feynman diagrams corresponding to this field and
show the equivalence of the classical and diagrammatic approaches. An argument
is given which demonstrates that at higher orders in g the classical
description of the process breaks down. As an application, we calculate the
energy, number, and multiplicity distributions of produced soft gluons and
reproduce earlier results by Gunion and Bertsch and by Kovner, McLerran, and
Weigert.
