"It is interesting to note that the men who, in the teeth of history, proclaimed that, if you want peace, you must prepare for war, were the self-same men who solemnly declared that Experience teaches, experientia docet-- or, as Mrs. Micawber more aptly put it, "Experientia does it." But as a matter of brute historical fact, Experientia generally doesn't. We got on doing what our own and our father's experience has demonstrated, again and again, to be inappropriate or downright disastrous; and we go on hoping (this time like Mr. Micawber) that "something will turn up" -- something completely different from anything which, on the basis of experience, we have any right to expect. Needless to say, it does not turn up. The same old mistakes have the same old consequences and we remain in the same old mess."
I am afraid that experience does teach “Si vis pacem, para bellum”
People for the most part are greedy, violent and dangerous and will be kept in check only by greater displays of force and violence IF all their needs are not met.
This is why we still have armies and police forces and why dictatorships not only exist, but exist by common concent of the people living within them.