2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/81912A model is developed for the hadronic and electromagnetic interaction in the two-nucleon system above pion threshold in the framework of meson, nucleon and $Δ$ degrees of freedom. It is based on time-ordered perturbation theory and includes full meson retardation in potentials and exchange currents as well as loop contributions to the nucleonic one-body current. Results for some selected processes are discussed.6 pages latex including style files. Invited talk at XVIII European Conference on Few-Body Problems in Physics, September 2002, Bled, Slovenija. Proceedings to be published in Few-Body Systems, SupplementNuclear Theorytext