I'd suggest this video as a good overview of why pure unmanned isn't the route countries are taking, and is unlikely to be the best option: https://www.youtube.

I'd suggest this video as a good overview of why pure unmanned isn't the route countries are taking, and is unlikely to be the best option: https://www.youtube.com/watch?v=1-0L5Wv86fQ https://www.youtube.com/watch?v=1-0L5Wv86fQ (and this video on manned systems that preceded it: https://www.youtube.com/watch?v=RPrWm6fWuaM https://www.youtube.com/watch?v=RPrWm6fWuaM as well) People expect manned-unmanned teaming to be the more likely thing, rather than just unmanned systems.