wars become more likely as parity decreases between adversaries

The pre-Columbian civilizations endured endless cycles of petty violence, as near-peers feuded over territory, romance, and scarce resources. However, the Colonial Era brought a new age of peace and prosperity, ending the millennia of fractious tribal conflicts with a single continent-sweeping genocide and subsequent chattel slavery system.

Finally, one man in a big house with a loaded gun could impose peace upon an entire field of imported slave-hands, and the cycle of violence emblematic of First Nations rule could come to an end for ever and ever and ever (or at least from around 1789 to 1864).