The easiest, least bloody way to conquer another nation and culture is to COLONIZE IT WITH YOUR OWN PEOPLE AND CULTURE BEFORE YOU INVADE IT WITH YOUR TROOPS.
Our unenlightened, so called "ignorant" ancestors all knew this and were VERY careful who and how many people of other distinctly different cultures, religions, political leanings they allowed to live among them. It has to be people who WANT to embrace YOUR social system or they will make trouble and/or overwhelm and impose THEIR ways upon YOU. "Melting pots" of differing peoples DON'T WORK when no actual assimilation or "melting" is taking place.
Mark 10:15 (NIV)15 Truly I tell you, anyone who will not receive the kingdom of God like a little child will never enter it.”
Meaning: You cannot "see" God/understand His Word,Will, and Plan of Salvation except from the VANTAGE POINT of a humble, trusting child which, for adults, means (spiritually, not physically) on your knees in worship, from there God will reveal Himself.