  We suggest an anomalous effective Lagrangian which reproduces the anomalous
conformal and chiral Ward identities and topological charge quantization in
QCD. It is shown that the large N_c Di Vecchia-Veneziano-Witten effective
chiral Lagrangian is locally recovered from our results, along with 1/N_c
corrections, after integrating out the heavy "glueball" fields. All
dimensionful parameters in our scheme are fixed in terms of the quark and gluon
condensates and quark masses. We argue that for a certain range of parameters,
metastable vacua appear which are separated from the true vacuum of lowest
energy by domain walls. The surface tension of the wall is estimated, and the
dynamics of the wall is discussed. The U(1) problem and the physics of the
pseudo-goldstone bosons at different theta angles are addressed within the
effective Lagrangian approach. Implications for axion physics, heavy ion
collisions and the development of the early Universe during the QCD epoch are
discussed.
