What would the army look like in the year 2313 ?

I would imagine it'll become more and more mechanised in the next 100 years (drones, robots, etc.) but also that there'll be no need for a conventional army once wars start being fought with computers. I.e. you won't invade a country any more, you'll just cut off power or water to their cities (when this is all computer controlled) or you will crash their economies.