Well, John, I suppose the best weapon system for you is the M-100 from the novel The War in 2020. Author Ralph Peters describes this vehicle as an armored tilt rotor armed with a magnetic cannon and equipped with ubiquitous awareness of the battlefield thanks to advanced computer processing and remote sensors. This machine gets past the weaknesses of the current US Army; while an M-1 tank is fast, incredibly well armored, and well armed, it has mobility problems in terrain like the mountains in Afghanistan.
The main reason we don't have anything like the M-100 is is the cost: with the war on, America can't afford to develop stuff like this. Then there's the political will problem, the current DoD leadership isn't going to go on an all out high tech research blitz. The other problem is identifying the enemy when they are insurgents that blend in to the population and use asymmetrical warfare tactics. Though an M-100 would be invulnerable to IEDs...
The US is doing a lot of work in the information gathering- processing- and distribution area so individual soldiers will know where their friends and enemies are. That will be a big advantage when these systems work in the real world and not just Clancy World.