  We further explore a recent proposal that the vector mesons in QCD have a
special role as Chern-Simons fields on various QCD objects such as domain walls
and the one flavored baryons. We compute contributions to domain wall theories
and to the baryon current coming from a generalized Wess-Zumino term including
vector mesons. The conditions that lead to the expected Chern-Simons terms and
the correct spectrum of baryons, coincide with the conditions for vector meson
dominance. This observation provides a theoretical explanation to the
phenomenological principle of vector dominance, as well as an experimental
evidence for the identification of vector mesons as the Chern-Simons fields. By
deriving the Chern-Simons theories directly from an action, we obtain new
results about QCD domain walls. One conclusion is the existence of a first
order phase transition between domain walls as a function of the quarks'
masses. We also discuss applications of our results to Seiberg duality between
gluons and vector mesons and provide new evidence supporting the duality.
