Well why I do believe that biological weapons could be unimaginably devastating, the problem is that biological weapons don't work on machinery or drones. If one side fights with biological weapons and the other side fights with machinery, the machinery will win. So knowing that, I assume that the warfare with advance to the use of machinery, particularly drones (robots essentially). I think one day, humans won't even really be fighting, already we're beginning to rely more heavily on ordinance, drones and other factors rather than mobile infantry.
What do you think is the best social structure? (IE: capitalist democracy, communist, dictatorship, etc)