Parallel Conductors - Magnetic Force

There are two thin, infinitely long current-carrying wires. The wires are parallel and co-planar, and are separated by a distance $D$ .

Consider two finite segments of wire of length $D$ ; one on Wire 1 (segment L) and the other on Wire 2 (segment R). The starting and ending points of the segments are "vertically" aligned as shown in the diagram.

What is the numerical value of the following ratio:

$\frac{\text{Magnetic force on Segment L due to Segment R current}}{\text{Magnetic force on Segment L due to entire Wire 2 current}}$