Multiple nation states are right now implementing AI at many stages of the 'kill chain' information passing and decision making structures of their militaries, in targetting systems, in all kinds of drones, land air sea... not to mention the actual Skynet type scenario of attempting to detect and intercept missiles.

In Terminator, the system like... gains awareness and escapes into everything computer.

We are just voluntarily putting it into everything, it wouldn't even have to really 'escape'... just have one of these systems majorly fuck up, and that'd trigger a cascading chain of other AI systems fucking up and or responding reasonably to some other system's fuck up.

...

There are other reasons for using AI in things like drones though:

You can jam a remote controlled drone, blast it with EM/radio waves to confuse the shit out of it, sever connection, or be more clever and hack into it, hijack it.

So... the cheap solution to this appears to be spools of fiber optic cables, sorta like a TOW missile, such that you just actually have a direct, wired connection the whole time.

But that obviously doesn't work at all ranges and for all types of drones... so... just let them think for themselves, what could go wrong??!