Near-tip plasticity is a significant and sometimes dominant contributor to the overall adhesion properties of multilayer thin film structures. In many technologically relevant interconnect structures, the plastically deforming layer is separated from the crack-tip by a thin elastic barrier layer. We employ multiscale simulations of such debonding by modeling a region around the crack tip where we apply local asymptotic fields as boundary conditions. The salient parameters governing interface fracture resistance (barrier layer, plastic layer and cohesive zone properties) are explored systematically. Of particular interest in the present study is the effect of high residual stresses in the layers on local fracture processes. These stresses have a variety of origins such as thermal mismatch strains and epitaxial stresses induced by island growth. We explore the effect of such pre-stresses on the decohesion process with particular attention to the relationship between the sign of the pre-stress in the plastic layer and the resulting macroscopic fracture energy. It is shown that the pre-stress can significantly alter the local debond tip deformation behavior and influence the macroscopic fracture energy. We propose simplified models to account for this effect.