Donuel, thank you.
My own opinion differs in this: what I observe in the human history of civilization, the little with which I am acquainted, is acceleration. The bloodshed of conquering empires is a constant of human civilization, I fear; and what has changed over time, is that society goes through these cycles of expansion, acquisition, consolidation, and the eventual undoing, at a faster pace. Is the British empire really so different, in its human impact, from the cycle of civilization in today's India, which reached its imperial peak in a much earlier epoch? I wonder if India, by whatever name it was called thousands of years ago, was not as bloodthirsty, ruthless, and acquisitive as a conquering empire, as the later empires to the West; it's just that India did all that rather more slowly, and by the time the English fought their way to the imperial summit, it was all happening a lot faster.
I don't mean to minimize or belittle the horrors of the 1900's with wars both hot and cold, especially not the loss of life, or the displacement of the survivors. It's just that when I look at the 1900's, I see layers and layers of conflicting social cycles intersecting each other. Things that in earlier history would have taken centuries to play out, burned themselves out in mere decades.

Funny, but in my own mis-education or ignorance, I recall that "choose your enemy carefully for you will grow to be like him" to be a paraphrase of Latin, from Rome's pre-Christian empire.