Anything that needs a quick reaction time with a man-in-the-loop needs that person in the aircraft as we have yet to overcome the speed of light.
Additionally, too many designers appear to think that:
- The EM spectrum has unlimited bandwidth at range.
- The EM spectrum is only used by them.
- The EM spectrum can only be used by them.
The US recognises the vulnerability of the space segment in any system, including GPS. Indeed, they are one of the very few that place technologies such as precision automated Astro-trackers on their strategic assets including aircraft such as the B-2, Rivet Joint, X-35B etc, as well as long-range comes that do not rely on satellites.
If we want unmanned fighters then we would have to give them autonomy and that would be a leap of faith for any nation that suffers from poor computer code, viruses, malicious hacking or rogue/disgruntled employees even before we consider any ethical concerns.