Hard processes in hadron-nucleus collisions are a powerful tool in order to investigate several important aspects of QCD in a nuclear medium, such as nuclear shadowing, parton multiple scattering or medium-induced gluon radiation.
I will introduce these nuclear effects and discuss how future measurements of quarkonium and Drell-Yan production in hadron-nucleus collisions, in COMPASS or at LHC energies, should help disentangling these various QCD phenomena.