The present F-18.
As newer platforms come on, the capability of the equipment we have to be seamlessly interoperable in an environment where you need to be very discrete with signals passage.... This is technology. How they detect our aircraft are there is quite often...by how we pass information between aircraft and platforms. That capability is becoming more and more complex, and the majority of our allies are in the process right now of fielding advanced aircraft. We will continue to have problems with our present F-18 fleet in being seamlessly interoperable.
There are many things that we'd still be able to do: processes, tactics, techniques, procedures. But in the aerial warfare in the future, that ability to be seamlessly interoperable is a key consideration.