Certain developments East vs West followed Newton's Third Law, e.g.
US develops Mach 3-capable XB-70 Valkyrie bomber
USSR develops MiG-25 to intercept it
US develops F-15 partly as a response to the MiG 25
But 'form follows function' is an important maxim; the Tornado (GR variants) are an optimised shape for low-level penetration, whereas the F-15, MiG-29 etc. have a shape and especially wing optimised for air-to-air combat.