All fighter aircraft will be fully autonomous by 2024 if there's a peer conflict. The real challenge isn't the technology but a risk and drone averse culture, so if say China or Russia decides they're at too great of a disadvantage and have little to lose from risking making all their jets unmanned, then this would force everyone else to adapt as well. Unquestioning robots that don't care about losses certainly are to the liking of totalitarian style regimes.

It's like in WW2 when the US rejected the idea of torpedo bombers to take out ships because they were convinced they wouldn't work (when their own testing proved that they would). It's not until the British and Japanese destroyed entire fleets that they adapted.

But now wars move so fast that there might not be enough time to adapt, the next Pearl Harbor might be called Washington.

On the technical side it's also not that hard, even the US has been flying unmanned jets, including F-16s, for decades. It's mostly a matter of developing the AI needed to manage them in a heavy jamming environment, but seeing as missiles and drones are already smart enough to execute complex missions to a certain level, it should be enough to automate all combat air vehicles to a high degree that they can defeat an enemy.

This can be very simple, such as China using mechanical autopilots to swarm Taiwan with unmanned J-5 and J-6, even with zero guidance and a high failure rate their simple presence will force Taiwan to shoot them down, or risk them crashing down filled with fuel and explosives, like modern day V-1 flying bombs, but probably accurate enough to hit an airfield or staging area.