Experimental programs throughout the world are generating increasingly detailed information about ion-ion collisions which require more theoretical effort directed toward determination of the operative dynamical principles. The proposed research will seek to explain the linear transfer of momentum in mass asymmetric collisions, to describe and to predict fluctuation phenomena, and to explore signatures for a quark-gluon phase transition in ultra-relativistic collisions. The other major thrust of this theory program is the development of a comprehensive and consistent description of nuclear structure at low excitations which gives a complete and reliable account of experimental information available from a variety of probes.