Why an unmanned fighter fleet isn’t yet viable, in the words of Britain’s Air Force chief

I agree with him, we're just not there yet. Option 1: it's a launch-and-forget jet with advanced AI and embedded ROE that allows it to legally kill humans under Title 10 USC without a human saying "OK". Pretty much Skynet from the Terminator series. Do we want that? Option 2: It flies without a pilot on board, but a human is still in the loop to make ROE and legal decisions on whether to hit a target or kill humans. This requires an RF linkage from human on ground to the jet, and all RF linkages are subject to the possibility of jamming, interference, or hacking, with the worst case being the jet is now THEIRS. Do we want that?