If you use robots to replace soldiers on a 1-1 basis, it's very very very hard. You'd need to have judgment programmed in and.. it would be very difficult.
Instead of that, simplify the problem and scale up your ideas.
My idea:
Invasion Mk II
1. Unarmed.
2. Fully location aware. GPS when available, inertial tracking when not, gyro stabilized, make every technology available so it knows WHERE it is at all times and records it.
3. Network connected. When available, use low powered ad-hoc mesh networks to connect to every other nearby IM2 robot to save on power and reduce RFI, at least one is designated to pump bits via satellite or any other infrastructure available back to secure digital storage in the states.
4. Full sound & video. Each drone records constantly, and content is either uploaded on demand or when certain triggers are tripped.
Example triggers: Sound of gunshot, explosion, etc. Sudden heat, etc. As bandwidth availability increases, maybe full time recording would be possible for all drones.
5. Mobile. Through any means necessary, full mobility is needed. Anywhere a person or goat can go, it needs to be able to follow.
Usage:
You dump millions of them over a designated area or at the borders. Each one parachutes or walks in and finds a person, then follows them. Through whatever technical means is available, it sticks to that person. If it ever loses them, it finds someone else and keeps going, logging the event. The end result is that everyone in the target country gets a data trail. Anytime there's gunfire, there's a log and evidence. If they shoot the robot following them, that's logged. If a robot goes into a bunker and never comes out, that's logged.
Everything is pumped into a big database, then the smart boys in IT start processing the information for patterns. Robots that seem to disapear more often near location X. Gunfire heard around person Y a lot, etc. Two car bombs, always when Person Z has walked through the area, etc.
Step 3: Profit. Send troops/assets/bombs as needed.
You could singlehandedly stifle any unconventional response (ie, terrorist) the same way you scare cockroaches, by shining a light on them. It's non-lethal on its own, so there's probably a BIG increase in accuracy and the number of innocents caught in the middle is dramatically reduced.
