You are referring to what is called Bygone History, that of our ancestors. This was the Pre-United Nations World, Pre-Space Age. Once we set foot on the Moon and saw the planet as a whole, long after slavery and genocide was abolished, we don't operate the same. We now operate with a Pro-Democracy, Pro-Human Rights Interdependent, Whole-Earth model. NATO is a necessary defensive organization similar to an immune system on a body and it has mostly worked. Religious delusional zealots have ruined the peace and now SINGLE autocrats are doing it too. We can't turn back time and no one is clamoring for expanded Empires these days except for one man.