A question of learning

"The Germans appear to have learned something from their failed attempt at claiming the Master Race title. We have learned little because most of our failures have taken place in distant places like Vietnam and Somalia.

Here, on Memorial Day, when we celebrate our military culture -- even though we haven't won a war in sixty years. We could learn a lot from Europe, in some ways."

I guess it is not so much a question of learning.
How can a Nation, whose economy is based on weapons´production, stop fighting wars?