World history, as we know it, is a series of footnotes on war. While it's interesting to know who invented algebra or chicken noodle soup, the historical record of humankind is overwhelmed by war and conquest.
Two great civilizations, Judao-Christian versus Islam, seem inevitably headed for a cataclysmic showdown, maybe within a decade. Pray to heaven, we have clear-eyed military leaders keeping a vigilant watch on radical cells of Islamic fundamentalists who might get their hands on nukes from Pakistan or North Korea.
Don't get lulled into a false sense of security because we've enjoyed an extended period of peace. Human history teaches us we are not one people. Like it or not, we are a warrior species. Hardwired that way over the millennia.