Abstract :
We review recent theoretical developments in understanding the many-body perturbative QCD dynamics of strongly-interacting hard probes in dense nuclear matter. The relation between initial- and final-state parton scattering in nuclei and the quark-gluon plasma and experimental measurements of the Cronin effect, nuclear shadowing, jet quenching, modified di-hadron correlations and forward rapidity particle suppression in p + A and A + A reactions is clarified. Our approach emphasizes the process dependence of nuclear effects and outlines the techniques for their dynamical calculation and incorporation in simulations that build upon collinear factorization in QCD.