  High energy scattering is considered within the framework of the QCD dipole
model formulated as a classical branching process. Starting from Mueller's
generating functional we derive the high energy evolution law for the
scattering amplitude. The amplitude's evolution is given by an infinite
hierarchy of linear equations equivalent to Balitsky's chain reduced to dipole
operators. This new derivation of the hierarchy is the central result of the
paper. We comment about target correlations which prevent the hierarchy from
being expressed as a closed form Balitsky-Kovchegov equation.
