Abstract: A unified treatment of the cohesive and conducting properties of metallic nanostructures in terms of the electronic scattering matrix is developed. A simple picture of metallic nanocohesion in which conductance channels act as delocalized chemical bonds is derived in the jellium approximation. Universal force oscillations of order ${\ensuremath{\varepsilon}}_{F}/{\ensuremath{\lambda}}_{F}$ are predicted when a metallic quantum wire is stretched to the breaking point, which are synchronized with quantized jumps in the conductance.