Carnegie Mellon Gets $14.4M to Build Robo-Tank
Notably, the communication system needed for this type of war machine is a mesh network of high bandwidth radio links (each robot would need several megabits, mostly for data from the video cameras) using electronically steered antennae to filter out jamming and allow for thousands of robots sharing the same slice of spectrum. All data would need to be communicated using a one time encryption pad. Radio spectrum being finite as it is, this is still (and will probably always be) basically impossible. You simply can't deliver high bandwidth to a large number of robots over radio. You need robots that use less bandwidth, and are therefore more autonomous, or you need a non-RF communication mechanism.