In this paper, the optical force between two circular plasmonic wires of submicrometer diameter (0.3 μm) with nanometer surface-to-surface distances (3-30 nm) interacting with radiation of a complex point source (λ≈0.2 μm) is numerically studied. Calculations (which are based on the Müller integral equations and the Maxwell stress tensor) show that an attractive optical force with a number of distinct peaks is created in distances 3-10 nm. However, for plasmonic-dielectric and plasmonic-reflector double-wires, the optical force has no such peaks. Comparisons reveal that the peaks are originated from the excitation of coupled surface plasmon polaritons in the gap region between the plasmonic wires.