Like every other institution, in a class structured society the ruling class insures that education serves their interests. In contemporary capitalist America this means the top goals are profit and power in the form of world hegemony. The latter means endless conflicts and wars. Thus our children need to be taught to have allegiance to military and other authorities, and they need to be taught that there are "evil-doers" out there that they must fear--only the police and military can protect them from these "evil-doers".
How did we become so manipulable and herd-like? So easily spooked into hysterical stampedes? So docile and ready to be driven by our government herders over the precipice of war?
In a word, near-universal compulsory schooling. In school, students are not so much taught as they are conditioned. Schooling deeply ingrains certain mentalities that foster militancy: timidity and tribalism, dependency and docility, conformity and credulity. And so schools sow the spiritual seeds of war.