Humans of all races  have always fought for resources, and with the advent of states and empires, fought on a grand scale. States and empires have existed on every continent, and in every race. Ironically, your mindset can only happen in people who take their eurocentric assumptions for granted and think as if the history of the world can be summarized by the last 500 years or so when Europe rose to dominance. Yes, 500, not "thousands" of years.

We know about the Greeks and Romans and Egyptians, etc. because they are at the root of our own cultural origins, but ask the Japanese, the Vietnamese, the Koreans, etc. about THEIR history and how well THEY all got along. Ask the tribes conquered by the Aztecs, Mayas and Incas, who collaborated with the Spanish because they wanted to escape the domination of THEIR imperial masters.

And in all those societies, the women were urging the men on, just as behind many islamic terrorists, there is a proud mother, proud aunts and proud sisters.